MTN Took all data and airtime - Cant tell me why????

A week before the end of last month all my data and airtime disappeared !!!!!! I phoned MTN nearly every 2-3 days, and gets a reference number every time, and them saying They dont know what happened but will sort it out and get back to me!!!!!! Two weeks and still nothing. I have been a client for over 10 years, always pay my account on time, and this is the service I get! I want this sorted out immediately and be compensated for what I have lost. My contract is due for an upgrade next month!!!! Why should I stay with a company that treats me like that! ref nr 1/ ********** 3010 and ********** 74, spoke to Amanda the last time I phone