Builders and RMCS

I would like to explain what happened to my mother on Saturday morning she and my sister went to builders to buy some building materials and later that morning she got an sms to say that there was a transaction that took place of R3999.00 and I went with her to builders to open a ***** case and when we got there we found Hlamulo who assisted us and called the number that was on the sms. We got through "Customer service", then we where referred to ***** department and we where told that the reversals will be done on my mothers behalf. About 6 transaction took place over the phone, thinking that the guy was assisting us only to find out the he is a *****ster himself. Later we got a phone a phone call saying we were talking to a *****sters. And said that they will lag call for *****. Today is Thursday and my mother got an sms to say that she is liable for all this mass. Only to find the the consultant was suppose to call ***** department on the back of the card not the SMS we got. Which means that the correct protocol was never followed from the store and now we have to pay for transactions that took place in the store while the consultant was setting in during the calls and never once said that this was wrong. And now we are found liable for this mass. Someone please assist