Complaint Review: Bank Of America

Bank of America, without my authorization and without my consent enrolled
me in to their business card security insurance last August 2008.

was abroad from the begining of August to end of November 08, my trip was
also informed to BOA, so as not to have problem using credit card abroad.

I had 0% apr bank loan from BOA payable in a year, so in my absence, they included business card security fee of more than $200.00 a month on top of monthly bank loan payment.
When I returned back,tried evey means to convince them it is not authorized
and no concent is made to enroll in business card sec.Insurance.

Between end of November and begining of January 09, I called BOA customer service more than 10 times to dispute their claim and cansel the plan.
After January 09 I have sent them additional 2 dispute letters but so far no response is proived.
The bank loan mentioned above was to be payed in full at the end april 09, but I paid it completly 11 days before the due date.

Now they are telling me I still owe them $617.37 for the business card security.
I used to be loyal customer and have never defaulted payment, infact I still have the title of prefered/advantage customer.
They ought to believe me when I tell them, I never asked nor agreed or authorized the insurance, besides they don't have oral/written evidence to support their claim.
how can they do this to trusting customer?
To make things worse, they are calling me constantly, threatning to report
to the credit agncies and spoil my record.

How can I convince the credit agencies not to spoil my record?
How can I stop bank of america from ripping me off?
Can somebody help?

Amas
college park, Georgia
U.S.A.