Why so long to fix my car? What do I do next?

SIX weeks ago, my car felt like it lost alot of engine power. Also, the heater wouldn't heat up. SIX weeks ago, the mechanic that handles MINIs and other European cars, said the turbocharger needed to be replaced. Also, some type of engine gaskets needed to be replaced, which is why the heater wouldn't heat up inside the car. I turned over my car to that repair shop SIX WEEKS ago, and they keep telling me that they have ordered the parts, but have not arrived yet from California. The gasket arrived two weeks ago, but (supposedly) it is the wrong size. Wow, is it normal to wait that long for parts? What should I do next? Tow it to another European repair shop? Is the repair shop trying to tell me something else like "We don't want to fix it, but we don't want to tell you the truth."