Infinity insurance Carol totaled by their policy holder but I get bill Nationwide

 my car was totaled by their policy holder. German rental car for 1 week. Takes them 2 weeks to offer settlement. The offered 15k for car Argued with out rental for week before they settle they offer $360 for compensation for week with no car since I had to turn in rental early. 3 months later get billed by rental car company because infinity never paid their rental bill. Call infinity they yell scream at me say the 360 was the rental I say no it was compensation for having to turn in the rental early. They say you signed paper saying no more claims when you accepted payoff. I said I had not received a bill for rental then and thought all was clear. They refused to pay the rental they authorized.