Cheetah Auto knowingly sold me a car needing an engine overhaul!

Cheetah Auto sold us a faulty Audi A4 1.8T (2011). We quickly noticed an oil consumption problem and reported it to them, they didn't care and refused to help. They recommended that we quickly buy an extended warranty (Must be *******). Audi confirmed the oil consumption issue of 1.43 lts oil per 1000kms!! We now sit with a vehicle that we having been able to use for months and can't afford the R80,000 to fix it. Please note the exemption clause in the Offer to Purchase!!