Is Mercedes Benz ZA, now using inferior materials in their cars? Plus a don't care attitude from service advisers.

My 3rd Merc has been nothing but a nightmare. I had two before the current one I am driving and they were a pleasure. I bought a pre-owned 2014 C180 with low mileage from Sandown Motors in Rosebank. The car had mechanical issues and they still released it to me. They reluctantly repaired it after several complaints. My Service is done at the Sandton branch on Rivonia road. This is where the drama is...my last service I think it was in Q2 - 2017. My driver seat got TORN, it wasnt when I left it there in the morning. I reported it to the service advisor who was helping me for the day, no love was given there. The car was then taken to upholstery to be mended. The stitching is of poor quality and not the same as the rest of the stitches in the car. MB Sandton didnt care as I had showed it to the service advisor. Nothing was done about the matter since, no follow-up's from them. The "unMerc" stitch has pulled the leather hard and now a second place has torn. So my questions are: Where is the Mercedes Benz standard here? Why is the leather tearing? Why is the stitching not as the original?

Apart from the ill service, in all the years I have driven Mercs this is the first car that has given me the worst experience, i.e service, material and driving experience.

I have tried to reach out to the head of Service there several times, but he is never available when I call. I guess not all brands(organizations) are Customer Centric.... I think its time to change brands, no more Merc for me, my family and friends.