@winoguy17, I have the answer for how and why that dirty LP you returned ended up back in the rack. When a retailer buys an LP from its’ distributor, it is a 1-way buy; that is, the LP is non-returnable to the distributor, for ANY reason, including being defective! I guess the store manager decided there was nothing to do but sell the LP again, hopefully this time to a consumer who isn’t an audiophile, or merely attentive enough to notice fingerprints on a "new" LP. The only other choice is for the store to "eat" the LP, losing the money it spent to buy it.
I always look for evidence of the "factory" seal of the shrink wrap on LP’s. Having seen LP’s resealed in the back room of a Tower Records (every one of them had a resealing machine), I know what to look for: the wrap is sealed on the edges of the cover, and there is a rough melted bead in the plastic on those edges. Factory shrink wrap often has the seal in the middle of the cover, with the two ends of the plastic overlapping. Resealing machines can’t do that. I also so look for paper stickers on the plastic wrap, which won’t be on a resealed LP.