Sales consultant mess up that i am paying for!!!!!!

After the sales consultant at MTN Groblersdal made a mess of my contract and instead of using my existing number to port to MTN and use as the contract number. He created a brand new number for the contract. I don't want a new number and after picking this up the next day i have been trying for 19 days to get some sort of response or time frame for when this issue will be sorted out. I have no doubt that they will charge me for a contract that i havent used whilst taking their time to solve the issue. All i want is for my existing number to be changed to the contract number. The manager refused to let me cancel my contract without paying a devise fee (all i want to do is change the contract number and i shouldnt have to pay for a mistake that wasnt my fault. ) The store also never answers their phone and ignores my whatsapp messages i send to find out what is happening!! I am beyond livid now and its been 19 days of a onesided battle.