Refund on double pos purchase

Paid my DSTV on 28/02/20015 when the electricity went off.The cashier said the transaction did not go through I have to re do it.The manager asked ,e to bring a bank statement to show that the first transaction was successulf from my account so that they can refund my money.<br> <br> I don't get any feedback as to what is the delay about my refund if I am going to get it or not.Efery day the manager calls head office but not able to provide me with the answer of what is happening.