Greentree Financial Greentree Servicing Misappropriation of funds , Internet

My mortgage is through Greentree Financial.  I requested the payoff amount of my loan, which was $7386.  I then sent them $7450, but instead of paying off the loan, they used $2330 of it to buy me another year of insurance (I still had 2 and a half months of insurance left) so that the loan would not be paid off and I would still owe them payments.  After a week of fighting with them, I finally got the insurance cancelled, but when I called their customer service to check on closing the account they were extremely rude and suggested that because I had gotten behind in the past they didn't have to do anything.  I believe this is misappropriation of funds and I'm still fighting with them.