The only ones who can do anything about this is Stoeger. This is a problem of barrel regulation and wil entail breaking the solder, realigning the barrels, and then resolder them back together. Unfortunately, it is unlikely you will get anything done as this is an expensive process in the first place and prohibitively so as a repair- especially on a bottom tier product. And that isn't considering the triggers if there is even anything that can be done about them. Odds are one of two things will happen: the gun will be returned to you with the company stating the gun falls within specifications or they will send you a new gun with odds being even at best it may be as bad or worse than what you have.
This is the bane of bottom tier firearms, especially SxS and O/U guns. These are quite expensive to build correctly as much of it requires hand fitting which is why decent ones are relatively expensive. To sell them at such low prices something has to give and that entailing hand fitting is the first to be cut. I think it was Bruce Buck who once said something like, "Don't check point of impact of both barrels of a double barrel shotgun. Whatever discrepancy there is will forever mess with your head."
