AUDI NEEDS TO TAKE OWNERSHIP OF THE DAMAGE CAUSED ON MY CAR DURING THEIR SERVICE

I've had my vehicle (Bought pre-owned Audi A3 TFSI) with under 20k on the odometer. It fell out of warrantee and maintenance plan because of the year model. I decided not to renew because I do not drive it frequently. took it for service at Audi Sandton Katherine Street on Wednesday 20 November. Had no issues, paid the full amount of R5117. On Sunday 24 November, I realize oil spillage in the garage. Upon driving it, I get a fault error of gearbox malfunction! This vehicle has never given me a single problem up until I took it to service. I slowly drove along through sandton and managed to get it back to the dealer (even though it was closed). I parked my car on their premises. Audi Sandton now says that I have to pay another fee to get my vehicle fixed, whereas it didn't have any problems prior to going in for service. AUDI NEEDS TO FIX MY VEHICLE AS THE FAULT OCCURRED ONLY AFTER IT CAME FROM SERVICE AT THEIR KATHERINE DRIVE SERVICE CENTER. THEY NEED TO BE HELD ACCOUNTABLE FOR THE FAULT ON MY VEHICLE AFTER IT CAME FROM THEIR SERVICE!