Merhabalar,
Alttaki kodda nerede hata yapıyorum, form post olmuyor, yardımcı olabilir misiniz?

<!DOCTYPE html>
<html lang="tr">
<head>
    <meta charset="UTF-8"/>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="author" content="Erkan AKGÜN"/>
    <title>Online Ödeme</title>
    <link href="assets/css/bootstrap.min.css" rel="stylesheet" type="text/css">
    <link href="assets/css/icons/icomoon/styles.css" rel="stylesheet" type="text/css">
    <link href="assets/css/toastr/toastr.min.css" rel="stylesheet">
    <link href="assets/css/icheck/custom.css" rel="stylesheet">
    <script src="assets/js/jquery.min.js"></script>
    <script src="assets/js/bootstrap.bundle.min.js"></script>
    <script src="assets/credit-card/dist/card.js"></script>
    <script src="assets/js/toastr/toastr.min.js"></script>
    <script src="assets/js/icheck/icheck.min.js"></script>
</head>

<body class="navbar-top">
<nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#">Sanal Pos</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
    </button>

</nav>
<div class="page-content">
    <div class="content-wrapper">
        <div class="content">
            <div class="card">
                <div class="card-header header-elements-inline">
                    <h5 class="card-title">Ödeme</h5>
                </div>
                <div class="card-body" style="padding-left: 2.25rem;">
                    <div class="row">
                        <div class="col-sm-6">
                            <form role="form" id="form-credit-card" name="form-credit-card" method="post" action="payment.php">
                                <input type="hidden" name="selected_bank_id">
                                <input type="hidden" name="instalment_count">
                                <input type="hidden" name="new_total_price">
                                <input type="hidden" name="card_type" id="card_type">
                                <div class="row mb-3">
                                    <label style="text-transform: uppercase;">TUTAR</label>
                                    <input type="number" class="form-control get_bank" placeholder="ÖDEME YAPILACAK TUTAR" name="amount" autocomplete="off" required/>
                                </div>
                                <div class="row mb-3">
                                    <label>KART NUMARASI</label>
                                    <input type="tel" class="form-control credit-card-number get_bank" name="number" placeholder="GEÇERLİ KART NUMARASI" autocomplete="off" required/>
                                </div>
                                <div class="row mb-3">
                                    <label>KART ÜZERİNDEKİ İSİM</label>
                                    <input type="text" class="form-control" name="name" placeholder="ADINIZ VE SOYADINIZ" autocomplete="off" required/>
                                </div>
                                <div class="row mb-3">
                                    <div class="col-xs-7 col-md-7 pl-0">
                                        <label>SON KULLANMA TARİHİ</label>
                                        <input type="tel" class="form-control" name="expiry" placeholder="AA/YYYY" autocomplete="off" required/>
                                    </div>
                                    <div class="col-xs-5 col-md-5 pl-0">
                                        <label>CVC KODU</label>
                                        <input type="number" class="form-control" name="cvc" placeholder="CVC" autocomplete="off" required/>
                                    </div>
                                </div>
                            </form>
                        </div>
                        <div class="col-sm-6" style="margin-top: 15px;">
                            <div class="card-wrapper"></div>
                        </div>
                    </div>
                    <div class="div_instalment mt-5"></div>
                    <div class="row mt-5">
                        <button class="button submit" name="save_payment">ÖDEME YAP</button>
                    </div>

                </div>
            </div>
        </div>
    </div>
</div>
<script>
    $(document).ready(function () {
        var card = new Card({
            form: document.querySelector('form[id=form-credit-card]'),
            container: '.card-wrapper',
            placeholders: {
                number: '•••• •••• •••• ••••',
                name: 'AD SOYAD',
                expiry: '••/••••',
                cvc: '•••'
            }
        });
        $('.jp-card-shiny').attr('style', 'display: none;');
    });

    $(document).on('click', '.instalment_select', function (event) {
        event.preventDefault();
        var value = $(this).data('count-number');
        $('.check_' + value).iCheck('check');
        $('.instalment_select').attr('style', 'margin-bottom: 15px; cursor: pointer; background-color: #fff !important; padding: 5px; color: #666; border: solid 1px #e6e6e6;');
        $(this).attr('style', 'margin-bottom: 15px; cursor: pointer; background-color: #eee !important; border-top-color: #f8ac59; padding: 5px; color: #666; border: solid 1px #e6e6e6;');
    });


    $(document).on('click', 'button[name=save_payment]', function (event) {
        event.preventDefault();
        if ($('form[name=form-credit-card]')[0].checkValidity()) {
            $.ajax({
                url: "payment.php",
                type: "POST",
                dataType: "JSON",
                data: $("#form-credit-card").serialize(),
                success: function (data) {

                    toastr.error(data['status'], "Cevap");

                }
            });
        } else {
            toastr.error("Kredi Kartı Bilgilerini Doldurunuz!", "Üzgünüm!");
        }
    });
</script>
</body>
</html>