Sim issues

I went into MTN at Cradlestone to change my current prepaid to a contract aswell as get a device. I was told that it would take a day or two for the sim to become active. After a week it still didnt work went back and had to wait over an hour just to be told that they will follow up and call me back. Two weeks later still no response i called them and was told they will call me back. Whole day has gone by and yet noone has called me back. Even if i call customer care they tell me I have to go back to the store. Why should I have to pay for your incompetence.