Absolutely hopeless

We took our Vito in for repairs as it kept on losing water with a brand new water bottle seemed faulty. They then took the engine apart and sent the heads in to be checked. No fault was found and it a new water bottle was put in with pipes. The whole exercise cost us 19000.00 to what should have been 900.00 + labour 1 hour. After receiving our vito back there was no compression so we had to bring it back in because they hadn't tightened a pipe correctly. When my wife turned on the radio it was not working and mercedes said that it was an after market fitting and that they could not do anything about it. I took it to an auto electrician who said that the wire had been cut and he rejoined it. We tried opening the sun roof which also has no power, the cigarette lighter does not work when charger's are plugged in. Total waste of money needless to say I now have to take it in to another workshop which will cost additional expenses and mainly I am to scared to take it to mercedes Boksburg for fear of them damaging something else.