Vodacom owes me money but wont pay.

Vodacom Garden route mall in George wrongfully deducted money from my account via debit order for a service I cancelled months before.. I went to the store 7 times speaking to the sales person and the manager. The sales person assured me that he would pay back my money as it was his mistake. He asked me for my banking details but never paid anything back. I then phoned vodacom customer complaints many times, everytime wr had a conference call with store where the sales person stated that he would pay the money a.s.a.p.. this never happened. On last call manager said he would get garnishing order against sales person to get the money but he never did it. Now vodacom customer complaints says there is nothing more they can do I must go to store. The store just promise but do nothing. This has been going on more than 7 months now.. and no one seems to have the authority to get the store to pay the money they owe me.. worst is the sales person and manager was recorded on all vodacom calls saying the payment would be made but vodacom says there is nothing they can do... no accountability, It seems they just keep promising the money without paying till you give up and write it off