Dang...sorry to hear to that. Mossberg is one of those companies you really hear the full gambit of feedback on. Some folks love them and claim that their barrels pattern extremely well. Others avoid them like the plague saying they simply don't like the "feel" of them. Either way, it's a shame they're not taking care of you on that.
My one and only Mossy experience was during my first year of duck hunting. I borrowed my father's Maverick Model 88 and took a kayak up into a flowage to jump shoot in October. Once I got what seemed like 3 miles from the landing, a duck went zipping by overhead and I decided I'd take an odd angled shot and then flip the kayak.
Long story short, Maverick went to the bottom of the murky flowage in about 8 feet of water never to be seen again. Once I doggy-paddled around a while trying to find a place I could get enough footing to stand up, I emptied about half the water out of the kayak and paddled back to the landing before hypothermia set in. That was an expensive trip after buying my father another Maverick at Wally's. That day, I was grateful to have taken the gun I did and not one of his others.
I've had some minor issues with my Benelli since owning it, but have found them incredibly well to deal with. (As they should, for the price you pay). Nonetheless, I've been impressed with all my interaction with them over the years.