AA baggage agent at DFW told me to pound sand on my old Kirkland Signature bag which had three damaged zipper pulls and was dirty like something oily had ran over it. I was only gold or platinum and don't know whether that'd make a difference. Probably too late to escalate now esp. since I replaced the critical one and just use zip ties on the others. Got too many miles on it to even consider seeing if Costco would replace.

Good to know airline is responsible. Thanks!