Cannot receive incoming calls

So, I have been with cell c for 8 years, I pay my bills on time. They notify of a roaming setting that we need to change because of merging with vodacom for better connectivity. This change of setting did not work for my phone. I now cannot receive calls, going onto day 6 now. I have phoned them 4 times! Given them 2 alternative numbers. They have not contacted me on those but closed the case because they cannot get hold of me! I STILL CANT RECEIVE CALLS BECAUSE OF THEM AND I BET YOU THEY ARE TRYING TO PHONE ME AND DID NOT TAKE NOTE OF THE ALTERNATIVE NUMBERS I GAVE THEM. You have my email address cell c, you send me my bills, sort my problem out!