Terrible service

I returned the vehicle on 31/12/2019 as per my booking. The guy checked the car while I was there and said everything is fine, however now they tell me the car is scratched and I an liable to pay for damages when the vehicle was already scratched when I received it. The vehicle was also overdue for service and short of coolant and the lady st the front desk advised that they are aware of the scratched bumper but there may be others. This was in cape town.