Worst vehicle buying experience ever!

We bought a vehicle from this company, collect it and drove it home, next morning there was a huge oil puddle under the vehicle and the engine light also came on. We took it back and after many arguments they agree to replace the gearbox. We had to wait for almost 5-6 weeks to get the vehicle back and many expenses later for hiring another vehicle. After we got it back the engine light was still on and we phone the owner again but the arrogant mr Liebenberg ignore our calls and messages. My question is how did this vehicle went through the roadworthy test? Think hard and twice before doing business with this company.