Was a sale, but not listed as a blem.
O cosmetic issue is one thing, a barrel this bad would be like calling a new car with wrong size bearings a "blem"
I was just curious. Sometimes they might catch one "blem" qualifying it for a discount, but then overlook another defect that's not cosmetic.
But, it's it's not a Blem item, that doesn't give any insight.
If it's that much of a problem, I would personally rebuild the upper and send it back as requested. They get to make the rules for issuing an RMA. I don't much like the RMA requirements most places email me when I ask for warranty service. So many hoops to jump through.
I do love the new Amazon return process where you do everything on the website, then drop off the item without a label, box or any other packing, and the UPS Store takes care of everything. For refunds, I usually see it in my account as soon as UPS transmits they received the returned item.

I get that it's a hassle, but is it really that much of a hassle to blow off getting them to inspect and replace it? Barrels aren't really cheap.
I've had some companies tell me to keep the old part and they sent me a new one as a replacement. I've also gotten refunds and told to keep the item I wanted to return. Different rules from various sellers.
I can't tell you what would be best for you, just what I would do if it were me.