Bad service

Good day <br> <br> I would like to complain about the services received from MTN, I had a contract which ended on 26 June 2015. I went to their offices on the weekend and they cancelled the contract and moved me to prepaid. I now have no signal on my phone and all my data that I had is lost. I cannot do anything with the phone. I tried calling the call centre several times and every time I get cut off. I am extremely annoyed and don't see why I have to put up with this pathetic service from MTN, from the beginning I have had problems with their services.