Poor Service and Negligence

I currently have an account at The Foschini Group, on the 3rd of April I paid my monthly installment of R760 via online and I usually use it and the payment went through.When I received the statement I couldn't see the payment and they also said it did not reflect on their side as well. I did received a notification payment from them. On the 6th of May I started sending them emails and I was requested to send proof of of payment .I did send all the the required information but I have not been assisted till today and its nearly two months now and the payment does not appear on my statement.