A package ticket has the wording "forfait" on the back which the AP office told us means its of no value basically as you get it at a reduced price as part of a package offer. You need a ticket that has a value printed on the back to be able to exchange for an AP. Also be aware that the ticket decreases in value as the days pass i.e. if you pay 80 euros for a 3 day ticket and go on day 1 to the AP office you get full value, if you go on Day 2 it decreases on a sliding scale.
Moral of the story - if you want to change your ticket for an AP do it on day 1.