The reason no one raises a stink is because many times, the insurance picks up the (Incorrect) TAab, so the consumer really doesn't know what things cost.

So..............First question the procedure against previous similar procedures with the billing department. Speak to a manager, not the first person that answers the phone (they usually are a step above basic clerks). Ask them what the difference was, and ask them what you asked for vs what they did. Fight it if you dont believe it to be accurate, and tell them you intend to take it to the insurance company for insurance fraud, IF they did something you didn't approve. That will get them going. Be prepared to break your business relationship with them if needed.