Too bad. What an unnecessary waste of time that could have been avoided by regularly checking the contents of the your Spheres and the Grid itself. I've got not sympathy for you, but I do have advice.

A) You really went out of your way to try and get Ultima.
B) The point of Ultima is that it is a late game spell.
C) Don't bother with it until you either:

a) finish the game
b) overlevel grossly enough to finish Lulu's section and head into Kimahri's