Don't feed him for 2-3 days. The Phoenix worms aren't terrible, but the wax works aren't great. Try introducing other works, such as silks and butterworms, since they are at least better for the chameleon. After 2-3 days, offer roaches, crickets, and other "hard" feeders. If he refuses, offer the better worms, give another break and try the hard feeders, again. If he refuses, offer nothing, but hard feeders, until he accepts. From then on. Offer worms, after he's consumed hard feeders and limit them to once a week or so.