Don't take sh*t from them. When you argue you can/should be forcefull but not stupid. By that I mean don't curse or yell. When that happens you lose all credibility. But you're someone who just WILL NOT accept a botched repair.
When stuff like this happens to me I walk into the place (whatever - a car dealership, electronic repair, etc.) knowing that since I brought my unit in to be fixed and it is still not fixed THEN IT IS NOT MY PROBLEM, IT IS THEIR'S. You can talk all you want but I'm not leaving until this get's resolved. If they are still being stuborn then take down all information. Names & positions. Manager, mechanic, customer service person, anyone you spoke with. Have as much info about WHO refused to fix your car when you need to go to Ford to complain.
A lawyer is a very good idea also if you can swing that.
Good luck.
