If it was in for an A or B service
then they probably forgot to reset the service indicator.
In general you're better off letting the dealer only reset this, until you are out of warranty. That way you get the maximum amount of service work done for free. But in this case, you could reset it yourself, if you know the A or B service was actually done.
I'd call the dealer to let them know you don't appreciate the indicator nor being reset. The instructions to reset it are in the manual. Let me know if you need help doing it. Or if it's convenient, take it to the dealer and have them do it.