Certainly a breach of my consumer rights?? Keeping Money which DOES NOT BELONG TO YOU!

On the 22/02/2016 and the 23/02/2016 I made 2 payments to settle my arrears account. Unfortunately I overpaid R739.94 - THE WORST MISTAKE EVER!!!!!! To date I am unable to get the funds paid back to me after numerous discussions with the "finance" team I am advised today that a cheque will be deposited into my bank account and I have to wait 7 to 14 days clearance!!!!! Under no circumstances is this acceptable -you did allow me to collect the funds at a Mr Price Branch, you refused to accept my email request without a copy of my personal bank statements and only after providing you with an account confirmation letter I am now told I have to willing just accept however you intend to pay men back MY funds which you have been earning interest on for the last 2 months !!!!!! I will not accept this and demand that this be treated seriously!!! Either pay me back my funds electronically or allow me to collect it from a Mr Price branch at my convenience!!!! A serious review of your customer service needs to be done.I can not understand that it takes a company of your magnitude over 2 months to sort out a simple request and then at your convenience and not the clients !!!???? This seems to be more at the convenience of yourself and none of my consumer rights are being taken note of????