UNSATISFACTORY SERVICE BY RCS

I experienced a ********** activity on my rcs card and reported the matter.I was given an email address to their ***** department .I explained why I suspected that something was wrong after I realized that the balance owing was now equivalent to the credit . I did not buy anything to that amount and has given no one permission to use my card .I have the card with me and I am concerned about what was bought ,where and which method was used to buy as the card was the only one issued to me .The matter was reported on the 8th November 2018 and nothing has been done or communicated to me on the investigation . I have not changed my contact details but I am very disturbed by the silence .Seemingly Rcs expect me to pay that amount ? H.S.Bokaba