Best Buy Geek Squad Continued charging fees to account despite cancellation Nationwide

After carrying the protection plan for a few months, I had called to request canceling the monthly renewal back in Jan. 2013 and was verbally told it would be cancelled.  Despite that - my card has continued to be charged for the last 18 months!!!  I called again in June, 2014, to again insist on canceling and to insist this time getting confirmation in writing. They gave me a reference number (since they cannot send out an email confirmation) - it should be cancelled now. However, they deny there was any previous request received and refuse to refund prior payments.