Highly upset

I went to mtn canal walk On 2nd November, purchased a sim and did a sim swop and got amazing service from friendly staff., 24 hours later my sim is still not activated. I called the store on the contact the number that was on the receipt, it just rang twice and stopped.I called and called,Googled numbers to call and go through a series of numbers even for the call centre,eventually I find a number that I can contact from a network other then cell c for contract customers and was told that the system shows that the sim swop has failed and that I should go back to the same store because if I go to another store, I will be billed again . Why do I need to go back ! I can also not go back because I have places to be at and need my number urgently. Why can't their be a better way to resolve this service that has been paid for but not delivered, why does it have to be fixed on my time and expense. The thing that posses me off the most is that you cannot get hold of the store via telephone.