Pumpkin, I'm sorry to say this is very much the standard policy with AT&T. Check out the AT&T forum for lots of horror stories (see Sprint & MCI, too !!)

In hindsight, the best tactic I have heard of is to put a block on your phoneline with your local phone company. Then ask AT&T/MCI/Sprint to fax or mail you the offer you agree to accept to change long distance carriers. When you receive the offer in writing, call your local phone company and authorize the switch. Then, it is no longer your word against theirs !

(FlyerTalk wisdom courtesy of other posters !)