NSW Purchased Car Privately - Refund Under Australian Consumer Law?

I recently purchased a used car privately. I asked questions in relation to any possible faults, only to be told, "No, it's ok."

I went for a test drive and returned to the seller's home. We negotiated a price, paid cash, completed paperwork and I left with the vehicle. I had noticed by the service sticker on the windscreen that the vehicle was overdue for service, so I bought oil and filters and did service.

I decided to call in on the service provider to see if there were things they had on record that would assist me in maintaining the vehicle. Enquiries with the service provider revealed a list of faults, such as big end, knock cylinders 2 & 3 low compressions, large carbon build up.

They then told the seller he could use a special oil to disguise the faults. Then said the vehicle has passed its usability date and that it was not worth fixing. I visited the seller and said to him that I wanted to discuss the vehicle with him and went through the problems, saying had he told me of the problems that the vehicle had, that I would have passed on the purchase.

I then suggested we resolve the matter by refunding my purchase amount and he takes the car back, to which he replied, "I have paid bills with the money" and denied that the service provider had discussed the matter with him. He also said he had some other person look at the car, but wouldn't tell me who.

I said I wanted to resolve the matter amicably under Australian Consumer Law and I have given him 24 hours to think about it and I would revisit him. I think it to be a reasonable request to refund my money and for him to take back the car