ارور Uncaught SoapFault exception

سلام و عرض ادب بنده کدها رو به شکل زیر زدم اما اروری که پیوست کردم نمایش داده میشه ضمن اینکه مرچنت کد درگاه زرین پال خودم رو وارد کردم و محدودیت ip هم نداره ممنون میشم راهنمایی بفرمایید 

در فایل panel-pro>views>panel>wallet>index.php

<div class="row">
                <div class="col-lg-12">
                    <div class="card">
                        <div class="card-title">
                            <h4>لیست کیف پول </h4>
                        </div>
                        <div class="card-body">
                           <div class="alert alert-info">
                               <p>
                                   <span>موجودی کیف پول شما :</span>
                                   <span>
                                       <?php echo $user_wallet; ?>
                                   </span>
                               </p>
                           </div>
                           <div class="payment-form">
                                <form class="form-inline" action="?action=payforwallet" method="post">
                                    <div class="form-group mx-sm-3 mb-2">
                                        <label for="amount" class="sr-only">مبلغ مورد نظر :</label>
                                        <input type="number" class="form-control" name="amount" id="amount" placeholder="">
                                    </div>
                                    <button type="submit" name="startpayment" class="btn btn-primary mb-2">پرداخت </button>
                                </form>
                           </div>
                        </div>
                    </div>
                </div>
            </div>

در فایل panel-pro>services>payment.service.php

<?php

class PaymenrService
{
    private $merchantID ;
    private $client;

    public function __construct()
    {
        $this -> merchantID = '88bc84d8-7472-11e8-8fbc-005056a205be';
        $this ->  client = new SoapClient('https://www.zarinpall.cpm/pg/services/WebGate/wsdl',
         ['encoding' => 'UTF-8']);
    }

    public function requestpayment($params)
    {
        $amount = $params['amount'];
        $describtion = $params['describtion'];
        $callback = $params['callback'];

        $result = $this -> client -> PaymentRequest([
            'merchantID' => $this -> merchantID,
            'amount' => $amount ,
            'describtion' => $describtion,
            'callbackurl' => $callback ,
        ]);
        $_SESSION['upp_amount'] = $amount ;
        if( $result -> status ==100){
            wp_redirect('https://www.zarinpall.com/pg/startpay' . $result -> authority);
            exit;
        }
    }

    public function verifypayment()
    {
        $authority = $_GET['authority'];
        if($_GET['status'] == 'ok') {
            $result = $this -> client -> PaymentVerification([
                'merchantID' => $this -> merchantID,
                'authority' => $authority,
                'amount' => $_SESSION['upp_amount']
            ]);
            if($result -> status ==100) {
                echo 'Transaction success. RefID:' . $result -> RefID;
            }else{
                echo 'Transaction failed. status:' . $result -> status;
            }
        }else{
            echo 'Transaction canceled by user';
        }
    }  
}

در فایل panel-pro>panel>handlers>wallethandler.php

<?php 
include "Handler.php";
include UPP_DIR . '/view.class.php';
include UPP_DIR . 'services/user.service.php';
include UPP_DIR . 'services/payment.service.php';
include_once UPP_DIR . "/utility/currency.class.php";

class WalletHandler extends Handler
{
    public function __construct()
    {
        parent :: __construct();
        add_action('upp_star_wallet_payment' , [$this ,'start_payment']);
    }

    public function index()
    {
        if($this -> hasaction()){
            $this -> performactions();
            return ;
        }


        $user_service = new UserService();
        $currency = new Currency();
        $user_wallet = $currency -> formattoman($user_service -> get_user_wallet($this -> current_user -> ID ));
        view::load('panel.wallet.index' , compact('user_wallet'));
    }

    public function payforwallet()
    {

        if(isset($_POST['startpayment'])){
            do_action('upp_star_wallet_payment');
        }
        view::load('panel.wallet.payforwallet');

    }

    public function start_payment()
    {
        $paymentservice = new PaymenrService();
        $amount = intval($_POST['amount']);
        $callback_url = home_url('/dashboard/wallet?action=verifypayment');

        $paymentservice -> requestpayment([
            'amount' => $amount,
            'callback' => $callback_url,
            'describtion' => sprintf('افزایش موجودی حساب کاربری به مبلغ %S' , $amount)
        ]);
    }

    public function verifypayment()
    {}

}