Old Republic Repayment of policy for services not rendered for Slableak incident San Ramon, California

In March 2010 the sewage pipe contained a break and caused the contents of the sewage to damage my basement and bathrooms.  I did not expect the situation to occur when I purchased the property in December 2009.  The cost for Roto Rooter to repair the damage was $4,500 which I paid with my credit card.  

I filed a claim under Plan Number 17-764-969 with Old Republic and to my surprise the company refunded only $900.00 with a $100.00 deductible.  On February 23, 2011,  I submitted a letter to Old Republic requesting a cancellation due to the policy that did not fully cover a $4,500 cost to repair a Slableak.  When I received the $900.00 check, I sent the money to my credit card company.

On March 3, 2011, I received a letter in the mail from Old Republic, they denied my request, however, demanding repayment of the $900.00.  The letter requested a payment of $416.66 to continue coverage until 12/16/11 or Reimburse Old Home Protection for the service cost incurred $816.66 less $83.34.

On March 3, 2011, I placed a call with the company and was informed that I will hear from a representative after the case was reviewed.  The renewal policy is only $500.00, I paid $85.34 on December 28, 2010.  I am not clear why they would charge me for cancelling a policy I do not  need for my home.

I certainly could appreicate your assistance to get a definitive answer concerning this problem.