If you have any sort of proof, witnesses, or evidence to support your case you could take it to court
what the say what did the judge say what did the cop report say an dinsunace compnies alway trying t get something they dont need to start with tel them to sue yoiu for it and then say dont call me anymore if you ws not at fualt the they have to prove it in court an djudge wil go by what was wrote in report
Tell them that without a court order you aren’t paying them anything. Especially if there isn’t a police report stating you were at fault. Having or not having insurance is not a determining factor of who is at fault. However, not having insurance can be a problem legally. You can be fined for not having any, but not by another insurance company.
I do not understand how you can drive a rental car without 3rd party liability