If the problem is just getting through to the contractors, try calling in evening hours instead of daytime hours. Because most contractors are busy doing their jobs during the daytime, that's when you're most likely to get voicemail or someone else answering. They usually return calls in evening hours. If they have 24 hour answering services, try telling them it's an emergency or very urgent. That sometimes gets the service to forward your call. It's also possible the answering service is the problem, and they lose messages. You can try writing a letter detailing your problems contacting the contractor.
I also try to prevent issues with contractors by paying in thirds. They get the first third up front to order materials to start the job, or they can have materials delivered directly to me that I pay for on arrival and stay with me...that way if they disappear, I still have the materials I paid for and someone else can do the job. The next third covers labor costs for satisfactorily reaching the halfway point for job completion, and the last third when I'm fully satisfied the job is completed as agreed upon. If there's a dispute along the way, I'm not out of money, and for them, they aren't out the cost of materials, just labor if I need to fire them.
As for the Better Business Bureau, I think they aren't very effective. Reputable companies usually respond to problems without them getting involved as long as you find the right level of support, and disreputable companies don't care. They have no enforcement abilities.
