Automark contact?

If there are problems with a car purchased via an Automark "certified used vehicles" dealer, how does one claim against this? Automark's call centre was unable to assist other than to advise that I should contact the dealer.

1. Query regarding RAV 4 purchased end 2014/beginning 2015. The first service done after the service plan and extended warranty expired resulted in horrific problems discovered, none of which had occurred over-night. Gearbox required replacement etc. Issues queried with the dealer over a year ago. No response to date.

2. Query regarding Toyota Corolla Quest 1600 purchased April 2018. An issue regarding brakes discovered two weeks ago after travelling 8000km since purchase. The service technician advised it is dangerous to drive a car in this condition.

In both instances, the dealer showed the signed vehicle inspection list but kept on file. I don't have copies.

Regards Liza