Lousy car hire company

In October 2018 I hired car in Cape Town . I had a slight accident on the highway into Cape Town (not my fault) the police were chasing someone and another car to get out the way crashed into me. The damage was very small. I reported it immediately to Thrifty and to the police. I never heard from them again except when I saw they had taken 4000 from my credit card. I was told that if they could find the other driver I could get refunded . That was the end I never heard from them again. I tried contacting them but never could. I had no invoice from them for extra payments . Now all of a sudden after nearly 4 years I keep getting calls from lawyers demanding money. I have told them to stop harassing me but it seems like every time its a different lawyer. AS I say to this day I have never received an account from Thrifty themselves asking for extra money. So I can only presume they are trying to **** me. I wont even try phoning Thrifty, which I did in the past and I have my emails to prove all correspondence. The car was a lousy little Datsun which no car hire should be hiring out anyway. Thrifty needs to get there lawyers to stop harassing me after 4 years.......I refuse to pay 1 cent more . They got their 4000 anyway.