Drivo Rent-A-Car complaint: False accusation of car with electrical issue having diesel gas put in it.

I rented a car at fox (Drivo rental car) for 28 days at JFK airport. On Nov 10, 2022. The car from very first day occasionally stalled after 3 weeks (likely an electric issue)I noticed it getting worse. Not wanting to deal with a car I couldn’t trust, I called Drivo to switch out car. They insisted I drive it back, so I did. I hoped I would get refunded for the day for the inconvenience. When I returned the replacement car on 28th day. I was asked if I had put diesel gas in the first car that had caused the electrical issue. (Diesel pumbs are larger and the cost of unleaded gas is double) I’m keenly aware of using the same gas station weekly and leaving the unleaded pump in, while figuring out the exact cost of each fill up to the penny. I of course denied the outrageous accusation. On Jan 23, 2023 out of the hour I was sent a $3,000 demand letter fir damages to their first car. 2nd notice written on it having failed to send a first one. And no details to the damaged and receipts of any kind. Both cars returned without a single stretch. I also requested of credit card that my $200 deposit be released. I would like an apology. If they had any evidence (invented or otherwise) they had in the contract agreed to by both parties to take me to arbitration were there absurd devious deceitful and cunning accusation and insane demand could be addressed.