At the park, it doesn't really matter from which bucket your theme park reservation was. It only matters that you have a reservation for that park on that date. If you were one who ended up with duplicate reservations after upgrading to AP, it doesn't matter which was used. If the park reservation was in your 5 AP allotment, using that now frees you to make another.
If you mean tickets and you had 2 types of tickets in your account but accidentally used the wrong ticket -- you will need to go to Guest Relations to get that fixed.