avis passing the buck

Had my courtesy car with AVIS via FNB, my car hire was till the 19 /08/22 and on the 18/08/22 at around 13H00 an avis recovery agent tracked me asked me to follow him to AVIS in Durban. I was told my days are over and if i need to keep the car for another day i have to pay an amount of R2000, i ask what for? i was told its for 2days extra. I was told if i don't pay the R2000 i cannot move the vehicle from there. My rental vehicle was fetched from AVIS kingshaka airport but i was forced to leave the vehicle at Avis Durban. They later realized that it was an issue and asked me to fetch the vehicle 5 mins be4 the branch closed, i had no transport to get there in time. NOW THEY TELL ME ITS NOT THERE ISSUE AND IM LIABLE FOR A LEAKING TIRE AND AN AUTO VALET. I was forced to leave the vehicle there even tho i had till the 19th to give back the car. NOW AVIS passes the buck to our insurance company.