Oh man, that's unfortunate! Customer service when dealing with a-holes is really the hardest part of just about any job.
I've got a horror story to share with you. 20 years ago I was the manager of an auto parts store, and these guys came in an bought a starter from me. No big deal, right? So a few hours later they show back up with this starter in pieces. For whatever reason, they'd completely disassembled their brand new starter. They thought (or claimed they thought) they had to take it apart to install it. So I put this thing all back together, bench test it right in front of them, showed them it works, and send them back on their way. A couple hours later they show back up again, and demand a refund. I say to them "You can't get a refund, you took the thing all apart and messed it up!" Well they wouldn't leave my store, I had to call the police to get them out.
Next day they call in and the owner gives them a refund. Because people have learned that sometimes when you're a big enough a*hole, you can get your way. But that doesn't make you any less of an a*hole.
And this is why customer service sucks, sorry that that really doesn't relate to your situation at all, but good luck reopening your store! :hammer: