Poor Service

My contract was migrated from NashuaMobile in November. My bill was incorrect billing and I was charged for services I don't have. I wrote to them several times since December. They don't even respond!!! My SIM card was swopped over a week ago, and is still not activated. I'be been back to MTN store Pavilion twice, each time they log it but it is still not active. Their reference numbers are pointless as i cannot get through to anyone at the call centre. The voice prompts on both 173 and 808 say they are experiencing problems, have high volumes, etc. and when i am allowed to choose, after several choice, i get put through to an operator line, which cuts off after aboit 3 rings - then i have to start over. Very frustrated!!!!