Henco Auto Check Centre Bellville - Beware - Bad service received and unacceptable attitude from the manager Mark Powell

On 2017.12.12 my mercedes benz was taken to Henco auto check centre at 83 Strand road in Bellville for a minor service. The vehicle was in perfect condition except for the service that was due. I spoke to Mark Powell the manager and I left my vehicle at the centre. They phoned me and told me that they saw a problem with the tappet cover gasket and I told them to fix it they did the job and I paid them R 1795.50 on 2017.12.13. I took my mercedes and when I started the mercedes I felt something wrong while idling I drove out of the parking bay and I was one block away and the orange engin light went on. I phoned the centre spoke to the secretary and she gave the phone to Mark he told me I can drive with the light on it is only a sensor that was faulty. He did fit a new sensor but he think the mercedes doesn't pick up the after market sensor, he would order a sensor from mercedes and fit it then the light would go off but mean while I must drive even if the light is on. He is the expert and I drove to Montague Gardens when I drove back the mercerdes lost power from 100km to 60 km on the speedometer I drove very slow to the centre because I was in Bellville allready. I went to Mark and told him what happened and he drove the mercedes into the workshop to check it out. He told me they will have a look and he took me home in his private vehicle. The next morning Mark phoned me and told me there is a huge problem now. He said they looked at the engin and the mechanic saw a problem that would cost me +-R15 000.00. I was shocked because my car was in perfect condition untill they worked on it. I told him not to touch my vehicle and I ordered a breakdown service of Odendal breakdowns to put my vehicle on a lowbed truck and drop it off at my house. Mark was at the centre when I arrived there and when the truck arrived Mark pushed my mercedes out the workshop for the truck to lift it up. We took my vehicle to my house because it coukd not even start I was furious because from a service to a non runner after a mechanic worked on my vehicle is unacceptable. Mark told me I can go report them if I want to they are covered by RMI he gave their tel number and email address I told him I want them to pay for my vehicle to be fixed because I held them responsible for the damage they have done since I left my vehicle in their possession. He said it is not their fault or problem if I want them to fix the vehicle I must pay them. I said I will not do that because after a servive they have damage my vehicle and how can I trust them now to fix it if they have broken it. I called another mechanic he was on vacation leave and I took my mercedes to him today he is still checking out what they have done to my mercedes. My mercedes is still a non runner and I was without a vehicle from 2017.12.15 up to 2018.01.17 waiting for my trusted mechanic, I feel Mark Powell and his mechanic can not be trusted and I must be compensated for my damages and losses and discomfort by Henco centre and I did not have any transport for weeks. I will be in contact if my mechanic let me know what is wrong with the mercedes and what the cost will be. Kind regards Nita