Shocking experience

I have tyre insurance with BMW, which I took up when I purchased my car. I hit a pothole and my tyre tore. I have been trying to get hold of BMW SA, BMW Insurance the whole morning with no luck. I've gone through to different receptions and receptionist who have transferred me from pillar to post, however when they do transfer my call, it rings twice and someone hangs up. At this point, I want to cancel that tyre benefit, as it is not working for me at all. THANK GOD I do not have comprehensive cover with BMW, imagine my life then. Can someone from BMW tyre insurance department call me, I'd like to cancel my cover thanks.