ZEP Application payed - Can't book an appointment Call centre can not help

I made a payment for my application on the 21st of October l received a payment receipt but l can't schedule an appointment as the payment does not appear on their website. After waiting for more than 72hours l called the call centre to find out why the payment was not reflecting on their website for me to book an appointment, l was given an email address which l sent all the information they wanted including the receipt. It has been a week now l have not received any response from them, l called the call centre again only to be told to wait until indefinate time. Can someone with valid information help as the call centre agents can not help, what they can only say is wait. I am disappointed, please assist with booking an appoinment as l have already payed.