said by hopeflicker:
They should flag accounts when a bill/usage gets to a certain point. This will force users to call in and inquire about no access, but they wont do this. They just want your money.
I agree and feel there is a responsibility on both parties. Firstly the users should, as others have mentioned, read and understood their contract.
I would expect a check every day or two on the online account would have revealed an issue to the account owner before it got out of hand.
I also recall that most cell companies have a credit limit when you open an account which determines how many lines you can get and under what plan. Seems logical that same limit would apply to usage.
At the very minimum you should get a courtesy call or SMS message indicating something is up when your usage is double or more the normal amount. Credit card companies do it all the time.
But $20k to send a gig of data? ATT can rot in hell for that one. I would have thought $300 was out of line.