So i did a trade on an exchange eth for lightning. It says paid on their end but i never got it. Initially my node crashed. So i have been going back and fourth in emails with support since it was a lot of money. They say they retry but it fails and ive opened up more channels there were adjacent to their node but no luck. They keep asking me for proof that i never recived the payment . all i can think of is the r preimage and screenshot of the innvoice to give them.
