I canceled AT&T DSL service on Aug 11, spending 36 minutes on the phone with them to to that. AT&T just sent me a bill for service for Aug 13- Sept 12. Called them again, spent another 18 min on the phone, clueless CSR said to just wait and not pay the bill, there should be another one coming that clears up that charge.
My guess is they send me a bill including a late fee for not paying this bullshit bill.