Incorrect data billing

Autopage is billing me huge data with no explanation. Just the last 48 hours has billed 1.2GBs with no unusual phone use. Mysteriously as soon as the contract is due the costs have multip****. For 3 months the billing has been excessive with no explanation. The response to this determines whether I stay with Autopage or port to a competitor. I also need to know what I have been billed for my device in the last 24 months. I have called the call centre 4 times and have been cutoff all 4 times before getting to speak to a consultant