Autobar damaging my vehicle after fitting of a tow

Took my car in to have a tow bar fitted. Before hand the car was checked for any damages and cleared. The car was taken in to have the tow bar fitted inside the premises. Took 4 hours to have the work done. After completion I was requested to review the work done and collect the car. The tow bar was tested and cleared as installed correctly. The sign off sheet was provided to me which I signed in good faith due to the tow bar working and fitted. Drove off. Stopped to do some shopping just to find that the luggage compartment lining was broken. I then returned immediately to AUTOBAR in Mayville Pretoria to show it to management. At my arrival Smithy (Manager who signed in the car), Bronwyn (Co owner) and workshop manager came out to have a look. Smithy confirmed that the car did not look like this and Bronwyn ordered him to take photos and VIN number of the car as she was on her way to Hatfield VW and will get a part to have it fixed. After 12 days calling them (AUTOBAR), every second day, I get hold of Jovanni (The owner), who claims that I broke the car and that it was my responsibility to check before I sign out the car. What a load of ****. Take ownership of your damage caused!