Alamo and AP discount

[DisneyIll]

I am an AP holder and want to apply the AP discount to the check out in Alamo but for the life of me I cannot get it to work. I have applied the code from the AP website and it will still not work. Anyone have any tips or do I need to buck up and call Alamo? I had to call them the last time I used them for another reason and they were not a least bit helpful. The last time I used them was with an airline package so I was not able to apply the discount.
Thanks in advance.