Most soddies aren't art knives. They are made to be used as tools. For honest, hard work.
With that in mind, I would do as others have suggested, and that is clean up the joints as much as you can. Make sure you flush it out good (when mine are gunky, I use brake cleaner!), then wipe dry.
With the blade halfway open, make sure you clean the exposed backspring as well. Inspect to make sure the surfaces are clean and free of debris there, too. My Queen soddie actually had burrs on the liner leaves that I carefully rubbed smooth with emery cloth. For that knife, the backspring/liner connection was the culprit for grinding, not the pivot joint. A little work on the grinding friction points and a dot of oil after smoothing and it is fine.
I also have Bulldog that is a really hard worker. It has great snap, medium pull and is a pretty knife. But when open, the backspring is about 1/16 of an inch recessed into the handle. It was annoying at first, but it doesn't diminish its utility value, and since I bought it to use ($22) I am fine with it.
You need to have realistic expectations. None of these are perfect in fit and finish at the utility level of pricing, almost all the good soddies are great users. Finding a perfect soddie is like finding a real pearl in an oyster.
I don't believe I would send it back to anyone as you might get one that is worse, and the postage alone would be about 1/3 the cost of a new knife. I would clean it up, oil it and use it until the blade was gone. Then go buy another one!
Robert