Contract sim card not working

I took out a new contract on Friday evening and the new contract had to be loaded on my already existing mtn prepaid sim card I had. I got the phone and put in the prepaid sim card and used the phone during the night. On Saturday morning I got an sms that my contract application was successful and that my contract minutes will be provisioned. From that moment I couldn't make calls nor go to the internet but could receive calls and sms. I called the 808 number from another phone to inquire and they told me its because my number is still pending on the system and that it can take 2-24 hrs. I waited and called again 808 and got the same message. On Sunday morning after 24 hrs there was still no change and I kept on calling again and getting similar responses from different people. Then its Monday now and still my sim card is not working and they still telling me about my number being pending and I should give it time. The lady at the mtn store i bought it has also tried to help me but to no avail. I'm thinking of cancelling the contract and returning the phone since its pretty useless but it seems like I have ruined my prepaid number which also had a lot of data in it.