I fed peas three times, I think, before they became "popular" within my tank. Definitely make sure you've taken off the shell, and I assume you're talking about frozen peas here, not canned or fresh. I've started dropping in a few whole peas, and a few that I've pressed in my fingers to soften them (for the smaller fish).
The first time I fed peas, I had to vacuum most of them up the next day. The next few times I had some left over as well, but not as many. Now I drop the peas in and the tank goes nuts! Everyone eats them, and I have barbs, a dwarf gourami, a loach, a pleco, a Siamese Algae Eater, and swordtails. The loach and pleco will suck on them until they've all but disappeared.
I'd try it a few more times before I gave up, if I were you.
Good luck,
Pamela