Cant receive calls from certain people after porting

<p>Ever since I ported my number over from MTN to Cell C alot of people cant seem to call me. I have called customer care a few times to resolve the issue but they have done nothing about it and always say they'll call me back but they dont. My dad cant even phone me for the past 2 years because of this issue. Now my contract is due for an upgrade and Cell C calls me very fast to do an upgrade but when it comes to resolving my issue they don't bother to call back or solve it! If the issue is not resolved I will have no other option but to cancel the contract rather than upgrading. I have been with Cell C for more than 11 years now and I must say this is an absolutely pathetic service towards a loyal customer like myself.</p>