Inneficient bad service from Jet

After many years overseas I decided to return home. After a while it was pointed out that I need to have a credit rating. So the decision was to open an account with the Edcon group and specifically Jet stores. I duly went and got information and opened an account. To my surprise after 3 weeks I get an invoice from them despite not having used the card and being told that any fees would only be app**** if I used the card for purchases. Upon furthrt investigation I found that I was indeed charged service/admin fees for 15 days in December and the whole month of January. I went to complain at the store and the manager called the "customer support" where I was handed the phone. I informed the operator of the situation that I was told that I would only pay service fees if using the card, I further advised them that on principle I would not pay these fees. I was informed that I would get a reply within 24/36 hours, but it being a Saturday I waited until Tuesday for a reply. I also advised them that I do not take calls between 9-5:30 while at work. Almost 10 days have gone past without ANY feedback. Now I wonder if my credit rating will be affected by a possible black listing. I feel that I am being held at ransom in a pay or else situation. It feels almost like I'm being *********ed