PLEASE GIVE MY MONEY BACK!!

I took out a 2 year contract with MTN in 2013. Close to the end of the contract MTN stopped debiting my acc &; I went into arrears,I then contacted MTN &; arranged that double debits were taken off for a period of 3 months to follow. I emailed Customer Services &; let them know that I was cancelling my contract as soon as it ran out. I received an email from Nandipa Sihawu @Customer Services letting me know that my contract had been deactivated in Jan 2015(Ref Num #***). Yet, MTN still debited my acc monthly after that until July 2015. I queried this &; Nandipa again assured me that my contract has been deactivated in Jan'15. Palesa contacted me asking for my banking details to refund me the monies owed. Till this day I have not received any money &; no one has contacted me. On 26.02.2016 I accidentally transferred R400 into MTN's acc. I immediately contacted my bank to reverse this &; they said that I needed to contact MTN directly. I mailed Customer care as well as Legal Direct with no response. Today is one week later and still no word. I really just want to get my money back and leave MTN in my past... I am super disappointed!