Damage claim that wasn’t me????

I recently hired a vehicle from tempest car hire at Cape Town International Airport. Upon arrival which was in the evening about 19:45, I proceeded to hire the car asking the gentleman behind the counter if someone was coming to inspect the vehicle with me, to which he answered that the vehicle had been checked and all was in order. First mistake. I then walked to where the vehicle was parked quite far and dimly lit area. I jumped in and rode away. The vehicle was parked in a secure complex for the evening, then I left at 6:30 when it was still dark and drove to a technical college that was close to the airport for an exam. After the exam which ran late, I drove back to the airport and dropped off the car, the inspector walked around the vehicle and gave me a thumbs up. I signed the paper and off I went. Upon landing back home I got an email about damage to the vehicle and that I must write an incident report?????? I was shocked as nothing had happened while the car was in my possession. Now they want me to pay for this damage? Hello peter is full of these incidents!! Maybe a story for Carte Blanche???