Response code No. 4 refers to a general decline error received from SHVA.
The decline is received from the cardholder issuing bank or your acquiring bank (your processor).
It can be seen in the dashboard (Payments --> Search) in the transaction details section under the Transaction Activity:
"description": "העסקה לא אושרה",
In case the error was returned for an Authorization or Charge requests, it points on a card refusal on the card issuer's side. Please ask your customer to contact the issuing bank/credit card company.
In case the error was returned for a Refund request, it points on a refusal generated in the acquirer's side. Please contact the acquirer and find if there is a limitation on the daily/monthly refunds amount.