Big Star Honda

I bought a car from here and needless to say it is no longer fit to be regularly driven. I am in the middle of trading in the car, but can't do so until my warranty purchased through big star Honda Is canceled. I have been trying to cancel it for a week, no return phone calls, no help what so ever, no cancelation has been done. I've filled out and faxed, mailed, and emailed the necessary forms and still nothing. I have been without a car for 5 days and this seems to be none of their concern seeing to as I have made numerous accounts to contact them and have gotten no response.