[NAHWheatCracker]

Regarding the customer, who knows? Unless they reply to you, you're guessing. It could be a legitimate case of a stolen card or they could deliberately trying use your service without paying. In this case, it sounds like you should indefinitely disable that user unless they explain.

Regarding the bank, I assume they will almost always side with the customer, lest they lose their business. There's no nuance, they aren't going to spend much time understanding your logs because there's no upside for them.

Regarding Stripe, I assume they are mostly passing along costs.

Given your chargeback rate, I don't see why you should lose any sleep over this, it's a cost of doing business.

[gtech1]

I'm more curious from the bank's point of view what kind of proof they wanted us to provide, and how can they not require any proof from their own customer