Audi DSG/S-tronic Mechatronic Unit Failure - cheaper temporary fix by dealership caused major damage

Audi diagnosed gearbox issues in April 2016 while under the Audi Freeway Plan and initially advised that the mechatronic unit (which controls the gears of the transmission) will have to be replaced - a pretty expensive job (R60000+). They said I will have to wait for 3 weeks for the part to arrive, which I was happy with considering that this is a major fix and should give me plenty of future milage on the vehicle. After a week of my vehicle standing stationary at the dealership, they phoned me back and said they will rather do a repair kit on the mechatronic unit - cheaper for them as it was still under the freeway plan and they will have to fork out the money. It also makes sense from their perspective knowing that the vehicle was only two months away from the freeway plan expiring and implementing a temporary fix should be just enough to get me over the expiry date - any further repairs would then have to be paid out of my pocket and not theirs - more money to Audi. They went ahead with the cheaper repair kit and I received my vehicle back. A couple of months later I started noticing some awkward issues - reverse gear struggling to engage and even loses power to the point where the vehicle lurches forward while attempting to reverse! Very unsafe! I complained about the issue to the service manager at the next service, but surprisingly Audi was not able to figure out what the issue was. Now, a couple of months have passed, the vehicle was back for a service, and behold they are now able to diagnose the issue - turns out the temporary fix they put in place while under the freeway plan has caused the clutch to take on damage and the mechatronic unit now needs to be replaced - something they opted out of. I now need to pay for the repair due to bad workmanship and decision making on Audi's part. The quote I received is in excess of R97000 and Audi does not want to take any responsibility for not replacing the mechatronic unit as the initial diagnoses recommended. Financial assistance from Audi has been declined. In this way they are *****ing from their customers - they do the least amount of repair work to get you through the freeway plan - very dishonest Audi.