Disgusting service to say the least

If I could give them a zero star rating, that still wouldn't measure up to the abhorrent service I have received from Telkom. I paid R5950 into their account on the10th of March, when I only owed them R11, I have been calling them since to get my refund, to this point I am being sent from pillar to post,with their turn around times changing at each instance I call them. It's excuses after another and no refund still. They are holding on to my money as though it is theirs.