I cannot for the life of me, as a non-us customer, understand one thing. This company has advertised an UNLIMITED service for $20 a month, and then gets all p*ssy when customers use it. If its not an unlimited service, they shouldn't advertise it as unlimited, then they wouldn't have all this trouble when they withdraw it.
Dunno about the USA, but we have laws against false or misleading advertising in the UK. Maybe someone needs to take AT&T to task.