shocked by the bad service and delay in refund

I have paid my home loan on the 31 Jan 2015, and unfortunately due to a technical error with Standard Bank's cell phone banking the ammount went through twice. I called the call center on Monday was request to send the request in writting, did as was requested called back and was advised that my fax was received and that the money will be refunded by today 6-Feb however surprise surprise nothing. I called them to quiry and was now told they need proof of payment yet it was done via cell phone banking, and each time i call back to speak to Dineo they cut the line and i have just wasted another R30 on them. Hope that they will resolve the problem soonest