I have entered my refund code several times but it has not been accepted. What should I do?

After six unsuccessful attempts, your refund code will be locked. To reactivate it, contact Customer Services using the contact form. 

Another reason why the refund code is not accepted may be because the refund has already been claimed. You can view all refund confirmations in the refund history. Please ensure you are entering the correct application number and corresponding refund code.