We didn't want to have a Fair Use Policy for this plan, Go Large had one and it didn't really work out for the best. So with that, we can't just kick people off for having high usage without stating its a possibility at the point of sign up. Which opens the debate of how much is too much.
People have obviously been using far more than you anticipated, which begs the question - when you developed this plan, how much did you expect people would use?
Clearly there is a demand for this type of plan, and people are willing to have their traffic shaped if it means they can have a higher cap.
I hope that you will be looking into designing a new plan that caters to the current BigTime customers. There has to be some middle ground?