First, I'm sorry you are getting jerked around...it sucks, and you often feel helpless...but you aren't. There are ways to get what you want. It just may take some time. The squeaky wheel always get's greased...unless the owner is deaf!
The Better Business Bureau (BBB) is a good service. No, they aren't "bought off". I'm sure it does happen, but it's not the norm. Companies enroll into the BBB so they can advertise the fact that they are members, not to keep BBB off their backs.
If you call the BBB, give them the specifics, they WILL get back to you. I won't go into big detail, but I had a problem with my home builder 2.5 years after I was in my home. My roof was leaking from faulty sub-contracting. I called my builder, they said NO, it's not in warranty anymore. I told them the roof was not built according to plan in that spot (valley) and it was going to continue to leak unless re-engineered. "NO", have a good day. I called the BBB, made a complant, and before that day ended, my builder was calling me saying that someone was coming out to fix the problem. They did. End of Story. Is the BBB fullproof? NO. But, it's free and they do contact businesses. Good luck man, keep us posted.