RSC Refuses to pay back my money

I made payment to my RCS card in June, I paid more than what I owed and wanted to close the account, I requested to close the account on the 8th June, sent documentation that was requested on the 12 June 2015, had to call to follow up, was told to resend my documents and did so 25th June, was told to send a bank statement and did so on 20 July 2015. today I called, spoke to a Mandy and she told me that on my profile it shows that I still need to send my documentation. she then put me on hold trying to confirm with finance until my airtime finished of which I think was her aim. I have never missed an instalment nor paid late, they debit from my account every month but it is a problem when they must pay back my money to that same account that they debit from, now all of a sudden I must send proof that I paid and statements to show money came from my account, why so much hassle and time when they must pay back but it is easy to debit a person's account? they are not professional, keep people on hold for long so I can give up due to not having airtime. No more