Unresolve and Ongoing Issue

I've purchased my Chevrolet a couple of months ago at Hyundai Bedfordview. The car was in excellent condition. A few months later after taking it in to the Dealer, GM Kimberley my car came back with an oil leak. I've taken it up with the floor manager who advised that he was personally going to make sure the issue is sorted which never happened. Took the car back for a 90 000km service and asked them to have a look at the oil leak. They told me there was no oil leak. Left my car standing for almost 2 weeks in my garage and when starting the car and leaving it idling you can see the smoke coming out of the engine. This is really poor service. Seriously if this is a money making scheme than I'd rather take it to a reputable back door mechanic. I'm not a mechanic but it looks like a defective o ring on the oil filter/connection. Best yet they never have courtesy cars available. If you work 100km from Kimberley they won't drop you off either. So you have to take leave and sit there till your car is repaired if ever.