DONT EVER SETTLE YOUR LOAN

I had a personal loan with RCS. I settled this loan on the 10th of September 2015 and e-mailed my PROOF OF PAYMENT to RCS the same day. I received an sms from them on the 10th saying that my instalment will go off, I phoned them immediately and told them that my account has been settled and that they must not deduct any more monies from my account. On the 28th they deducted the instalment which I only noticed on the 30th. I phoned them again and was asked to send a bank statement showing the deduction. I sent them this showing the settlement on the 10th and the deduction on the 28th. I phoned them again this morning and now they tell me that my bank statement is invalid as the dates do not follow. Why must I send them my whole bank statement? That is my private business. I copy and pasted the dates that is relevant to them. I have made numerous calls since then but still have not received my refund. Who is going to refund me for all my telephone calls that I have to make and hold on for 20min at a time to GET MY MONEY BACK. Does the accounts dept not know their **** from their elbow. The account was SETTLED on the 10th, why deduct money again on the 28th.