Had this happen once.
Bought a youth size .22 rifle that allowed gas to blow back on the shooters cheek.
When I contacted the company, telling them I thought that was really bad for a beginners rifle, they sent me a new one. They explained that they were haveing a "problem" with certian brands of bulk boxed cheap ammo in their guns. Just happened I was using that ammo.
The replacement rifle comes in the next day DHL.
Now I called the company back (Spoke to the Vice President both times...they were excellent as far as that went) I told them I couldn't just keep the gun here in Massachusetts, that I had to receive it through an FFL. They asked me what I wanted to do, even offered I keep both guns (I should have).
What I finally did was bring the first rifle back to the dealer I got it from. He did up a FFL sale for the new gun, and shipped the old one back no charge to me.
The rifle manufacturer reimbursed my FFL for his costs.
PS, the rifle has been sitting in my safe in the box ever since. One of those things I just have a bad feeling about. It's so small I can just about use it as a pistol, all stainless and synthetic stock at just over 3 pounds. I guess I'm keeping it for an EOTWAWKI gun so I can travel light