How to handle threatening customers?

Hey guys, I run a very legit fashion brand. We have a pretty classic 30 days return policy, and clearly state that if the goods are damaged, stained, or have odors, their returns will be rejected.

Almost any time we reject anything, the customers freak out. One customer provided me 4 shirts back, we had to deny one from stains, so he's getting a 75% discount.

He's saying he's reporting us to the attorney general, doing a chargeback, and screaming from the mountains. I even told him I'd meet him in the middle with a partial discount and he continued to berate me saying I'm a scam and playing games.

Pretty much all rejections go this way. Any advice? Can I win? We document everything and take pictures of our returns in warehouse