8" low and left compared to the other barrel? Your gun is not properly "regulated". (both barrels adjusted by the maker to hit the same point of aim at a given distance)
The classic shotgun standard for patterning is a 30" circle at 40 yards.
Guns with no names tend to be "budget" guns (no matter what you actually pay for one), and the maker may not have done a proper job of regulating the barrels.
Try a few shots on paper at 40 yds just to see if the gun is still shooting one barrel low and left (and how much), also try some different loads, to see if the gun does it with everything, or just one kind of ammo.
If its does, and under warranty, send it back.
If sending it back isn't practical/possible, then you need a good gunsmith. Generally speaking it can be fixed (the gunsmith can tell you if its possible, or not, some guns its not "practical").
The process is labor intensive, as an adjustment has to be made, then the gun has to be fired (with ammo equal to what you are going to use), pattern checked, then adjusted again, shot again, etc., until both barrels are shooting to the same point of aim.
Generally it can be done, but it might cost a lot. Most run of the mill gunsmiths, local gun fixers, etc., are not set up for this kind of work. You need to find the right guy for this kind of work, and talk to them about it, before you decide. The cost of a few phone calls is nothing, compared to what you might have to spend to get the gun properly fixed.
Good Luck!