Poor and *********** service

I took my vehicle on Monday the 4th of November where I went on Friday to collect the vehicle I noticed that parts used were not genuine parts from the dealer despite the fact that I had doubts if they were new parts as they didn't look new. They created a story that my front wheels were to big I need to change them. Surprisingly the vehicle has been using those wheels for the past 15 years as it came with that specification from Mercedes Benz from the date I took the position of the vehicle in 2005 and I was the first driver. it was clear the problem were the shocks fitted and I asked them to take the vehicle to AA for confirmation that (i) The shocks are that of Mercedes Benz(2) that the shocks are new without any damage to them and they refused citing that their policy does not allow them to go to the third party whilst they claim that shocks were fitted by Supa Quick which is the third party and therefore their argument has not substance. They took back the vehicle on Monday again but still couldn't resolve the problem and the vehicle was delivered on Friday 08 November 2019 with no resolution to the problem.