Paying fot MTN's FAULTS!

I have never experinced a problem with mtn until now. The type of treatment I have received is appaling. For as long as I've had my mtn line, I have been bothered by creditors of a man by the namen of Gaven De Wee. I receive endless calls and smses everyday telling me to pay up or demanding to speak to Mr G De Wee. I would take the calls and tell them that its a wrong number, hoping it will stop but it hasn't and it has been 3 years now. I am now tired of being bothered by this mans creditors and urgently need my number to be changed. I called the call centre and they advised me to go to an mtn store to receive assistance. I then went to MTN Jubilee Mall in Hammanskraal and there was a young man standing at the door whom I explained my predicament to. He told me that they must do a number swap and I must pay R250. Why am I supposed to pay for MTN's mistake when they are the ones that gave me a recycled number is what I asked him and he told me that numbers are finished, which doesn't make sense because my partner was recently given a new 060 number which was system generated. So why can't the same be done for me? I've recently even upgraded my contract with mtn but I'm even thinking of cancelling it because of the trearment I'm receiving.

It's not my fault that this has happened, so why should I pay? I should be treated better than this honestly