I'm a constant bolt breaker, myself, and had very similar fears when I got mine. The grip was loose when I got mine, but managed to snug mine quite well. It must have been a QC issue on that lot, because I cranked the living $hit out of mine to get it tight, and it never popped like that. I know it happened during the installation of after-market parts, but can it be fixed under warranty? If not, try the store you bought it from. Nobody likes bad publicity and in this day and age, customer relations is key to the success of a dealer.
Other than that issue, I totally love mine. Don't judge the whole line of rifles by one bad one. A non-restricted AK variant clone isn't easy to come by in this common-sense forsaken country.