have you tried making the hole where the mag release fits into the mag bigger?
I had a similar issue with some socom gear mags and my XCR-L had to file down some tab inside the magwell to make them fit. they fit snug and with a little wiggle came out..
"You know what the chain of command is? It's the chain I go get and beat you with 'til ya understand who's in ruttin' command here."