Bosch Car Service Gezina - Disappointing and poor service

I bought a pre-owned Mercedes with an additional warranty in 2019. The warranty dictates I should have the vehicle serviced at an MRI accredited dealer. After some Google searching and asking around, I decided to take the vehicle to Bosch Car Service in Gezina, Pretoria even though it is rather far from my house. Upon making the booking I was told the indicated B7 service includes changing of all filters and oil including the gearbox oil and was quoted R6700.00. I agreed and took the car there. At this point I must mention there was absolutely nothing wrong with the vehicle, no error codes, not using oil nothing whatsoever. During the day I received a call informing me the vehicle is leaking oil and needs a sump gasket as well as a new wheel bearing. The additional cost would be R10k. I said to hold on and immediately proceeded to phone around managing to source the complete wheel bearing set (***) and gasket for R1700.00 total. I therefore told them to only do the service since I thought they were asking too much for the additional work. I collected my vehicle and was charged the full quoted amount. Upon scrutinizing the invoice I saw no mention of gearbox oil and filters. When I asked the representative I was told they checked the oil and was still clean there was no need to change it. I also noticed they use semi synthetic oil which is NOT the oil recommended by Mercedes. I asked about it and was given the BS story it only says semi synth on the invoice but they in fact use full synthetic oil. By the price of the oil I could see that was not true. At this point I asked to see the workshop Manager but was told he was in a meeting (total BS of course). I left and on the way home I suddenly had a vibration in the drivetrain which I never had before - the "worn bearing" they mentioned suddenly sticking it's head out after the service? Very suspicious. Anyway, the next morning I noticed a pool of water under the front bumper. I opened the bonnet and saw that is the position of the windscreen washer bottle which never leaked before. I took the vehicle back to Bosch and was told I'll have to leave it there three days because they basically have to strip the car to check the bottle. Of course I need the vehicle so I did not leave it there. A few days later I decided to check the oil just as a precaution - and discovered the oil had been totally overfilled. The entire dipstick (and more) is totally flushed with oil. Now anybody who knows anything engines knows how bad it is to overfill the engine with oil. So, there you have it. That is the kind of service you can expect from Bosch Car Service in Gezina. I cannot in good conscience recommend this dealer to anybody.