Selling cars without disclosing faults

So we bought a car September 2020.

Due to lockdown we have only driven 5000 km to date.

Our engine light came on and after running a diagnostic test on the car, besides the fault that made the engine light come on, there was a fault on the car that was picked up in 2019 already and we were not informed of this, and of course our warranty plan won't cover this as the plan was purchased after the fault was picked up.

Car dealership just says sorry our 6 month warranty has passed.

This fault is now going to cost us roughly R15000 to fix!

To me, this is extremely ********* and just goes to show that their sales people are only there to make money, not to actually assist clients!