RCS ********** transaction

Hi I have a Makro card which I have not used for more than a year. On the 25th of June this year I received an SMS that there was a transaction of R3000 done on the card at Foshini. The card was in my possession and I never did this transaction. I called RCS and reported the ********** transaction and they sent me the documents to complete and return to their dispute dept , which I have done twice now. Up to this day they keep on calling me and sending SMS 's for demand of payment ,no matter how many times I explain.