Edgars refuse to refund

I have had an edgars account since 1997, I was then unable to pay my account which was handed over to attorneys. I made a payment plan which I adhered to until I paid the account in full. I only realised that I overpaid the account and called Edgars. I was told by customer care to brING bank statement, copy of ID, proof of residence & letter requesting a refund which I did in June 2015. I called again when I didn't get my refund and was told they did not receive the doc I left at the branch and was told to now bring confirmation letter from the bank which I did today at cresta.The story changed again that they actually need 3 months bank statement. This is really upsetting as I need to have closure on this matter but I'm not getting any joy even the don't care attitude from the staff. I plan to go to any length to expose those who are not doing their job and get my money back. When I was unable to pay I got all these calls to pay now I don't see why I should beg for my money acc: