They don't give any info about tickets and their value over the phone for some reason. In my experience on the Universal boards, everyone's tickets have been given gate value when applied towards an upgrade. Tickets from UT and other third parties and loyalty groups have all been treated the same. We've had our AM tickets upgraded to APs a few years ago and intend on doing the same again this October.
Did you use the tickets first before upgrading, or just take them to guest services before using?