Refund

I sent my proof of payment so that I can get a refund. A few days later I called Vodacom to find out how long will the refund take. I spoke to three different people, one said 48 working hours, second said 7 working days and the last lady said 14 working days (clearly it takes as long as they want it to, no one really knows). Anyway, the lady then says the i have provided them with an incorrect proof of payment (they need it to show my account number). My question was if I had not called you, who was going to inform me to provide you with the correct proof of payment? She said the only time that Vodacom will have access to the client's account is if the client calls in to do a follow up. So basically my matter would have sat with Vodacom for weeks with no feedback had I not bothered to call in? Am I supposed to wait 48 working hours, 6 working days or 14 working days to get the refund?