Overpayment not refunded

I overpaid my X-ray account by adding 2 extra nought's. Instead of paying my R713,65 account I paid R71,365.00 in error. I immediately phoned their accounts department and was told they could no nothing. My bankers said that due to it being an Eft they could do nothing. After 3 weeks of stalemate I still have not received a refund. I completed the necessary forms for a reversal via my bank (RMB) to their bank (Standard Bank) and have just been told that Standard Bank has rejected the request!