Hyundai Service

We bought our vehicle from Hyundai Durban August of last year (Used vehicle, 2013 IX35 CRDI). We realised there was something wrong with the car taking off and upon inspection from Hyundai were informed it was the flywheel which would be replaced under warranty. As we were living 400km from Durban at the time we were only able to have this replaced in March. We then took the vehicle to Hyundai Umhlanga for the 150 000km service 23rd of last month and on the report it states noise from the flywheel again, and we've noticed that the car is shuddering again when taking off. When we informed Hyundai Harbour view (because we were just under the warranty) they said they would need to inspect the vehicle themselves. We've had the vehicle back at Harbour View today and they are telling us it's the "cam belt slipping". Either Harbour View is trying to get out of repairing the flywheel again (as it's a R20k repair) or the mechanic at Hyundai Umhlanga is not qualified as he inspected the car and said the flywheel needs to be replaced (which from past experience, that's exactly the problem). So which Hyundai here is in the wrong as I definitely don't have R20k out of warranty to replace this flywheel!!!!!!!!