ULPT: Bank keeps denying my fraud claim

On 4th of July weekend I was out and about downtown getting drunk as fuck in the hot summer sun. At one point, a guy came up to me saying he was selling water bottles for $1. I told him I didn't have cash. He told me he took cards. I wanted some water at this point and asked for a bottle. He pulled out one of those tiny white card readers a lot of merchants use, and I tap my card and take my water.

Maybe 5 minutes later, I get to where I needed to go and took out my phone and see a $500 charge to my credit card. I called the bank immediately, and they said they couldn't do anything until the charges post. Two days later, the charges post, I file a dispute, they ask for evidence, but I didn't really have anything to give them beyond a police report I filed.

About a week later, I was told my claim was denied. Apparently, these sorts of disputes where you werw present for the charge are really hard to appeal without any sort of evidence.

I ended up doing some digging and was able to track the guy down based on the business name on the bank statement. It was 100% the guy and I found his email, Instagram, Facebook, and phone number. I tried contacting him every way I could and he either ignored or blocked me. I sent all of this to the bank and they're still claiming it's not enough evidence.

I still have a chance to appeal this, and I'm genuinely curious how fucked I would be if I just used inspect element to create some fake correspondence. Some sort of message chain like "hello kind sir, I did not agree to give you $500 for a bottle of water, please return my money" followed by "ayyy fuck you man you ain't getting shit. Next time don't trust other people with your money lol".

Do the banks have their own way to verify if messages are legit or not? I'm not really sure what to do here.