Poor/No Service from Renault

I took my wife's Renault Captur 1.2 Turbo EDC to Renault Centurion for a knocking sound coming from the gearbox. After they had the car for the whole day, the feedback was they couldn't hear the knocking. I discussed it with the Service Manager who suggested that I book the car in again and they will investigate. The feedback I got later in the day was that they think the electronic controller had to be replaced. They would order a controller and when it arrived, I had to book the car in again for the replacement of the electronic gearbox controller. After the controller was replaced, the sound was still there and when you engaged reverse, the car would first move forward and then backwards. I immediately reported it to the dealership and guess what was the response? "Book it in so that we can have a look". The car was booked in yet again. Later in the day I was informed by the Service Advisor that the clutches on the gearbox had to be replaced and that it was for my account (on a car that supposably have a 5 year warrantee?). After lots of to'ing and fro'ing and arguments it was agreed that I only had to pay for the "wear and tear" on the gearbox. Please explain to me how the user of the vehicle can cause "wear and tear" on an automatic gearbox? The clutches were then replaced by an external company because Renault "don't have the tools" to do the job. There was some improvement for a while after the clutches were replaced, but then the moving forward and then backwards after the Reverse is engaged started again. It was yet again reported to Renault Centurion and guess what was the response? "Bring it in so that we can have a look". The vehicle was booked in yet again but there was absolutely no improvement detected and it is getting worse by the day. When I wrote an email to the Service Manager to complain about this as well as a door rubber that was damaged while the car was with the dealership, I was advised by the Service Manager to take it to another dealership. I then wrote a complaint to Renault SA, I had no response. I tried calling Renault Customer Care, they don't answer the phone. The bottomline is, don't expect any service from Renault when you need them!