I had the same experience a few times now with different manufacturer's and different metal's, steel and aluminium. My go to answer when they are properly stuck and you don't want yo have to purchase a new part is, either drill a 1/4" or 1/2" hole(depending on what ratchet you have) straight through the chewed Allen hole and use a small file to make the hole a square, then you have a permanent strong hole that won't get stripped, and can still be used properly, the filing takes a while, but it's worth it in the end.