MTN so many problems

In November I took out 2 new contracts and asked that an existing number be changed to pay as you go. The number has not been changed. I am still being charged for my contract. The store I used cannot help. I live overseas and am told to contact a number that puts you on hold. I have roaming charges when the sim was not even in a phone. On the two contracts that I took out I have been charged but one number did not receive the data and airtime.