Lies, deception, my car used for private purposes, dealer takes no responsibility

My car went in for a warranty gearbox repair between Renault Knysna and George. After a lot of lies from the management and 2 months later I received my car back with damages on the body, empty fuel tank and 591 km's driven extra without my knowledge and consent, mileage between dealers and gearbox repair center excluded. Gears are now difficult to select too. Seaman's Renault owner's response to km's drive, "I don't know if I can do anything about that". Pathetic service and management. Contact me if you need more info, I have everything on record, emails and call recordings.