I am punished for their error

I have not has such horrible service in my life. Firstly they over bill my account and now that they supposed to refund me my MONEY they want me to run around like a headless chicken. They asked me to send them a proof of payment so I ask the lady I spoke to last week if a bank statement will be okay and she said YES the bank statement will do, so I send me bank statement and then there was silence. After 5 days I decide to call them to follow up on my refund and I am told that I must go to a vodacom shop to get the slip so if I didn't call them who was going to tell me that. Vodacom was happy to get the money but that they have to pay my money back to me they giving problems. To all the people that have a contact with vodacom just be sure to check your account and make sure that you are not over billed, vodacom is ******** people