User Activity

Scenario - I deposit $100 into my prepaid account - Bell takes a monthly charge + taxes and fees based on the plan that I have selected .  How do I get documentation of the monthly deductions Bell takes from my prepaid account?  All I can see in the ...
If I have a prepaid plan for 100 minutes per month why can't Bell use an automated message to interrupt on the call that is about to go over the 100 minute mark and tell the customer the 100 minutes is about to be up?  Could you not at the very least...