Loan on my house

On August 2012
I called Reliance to buy furnace and AC. Next day came a lady her name is Bitty. and she show me two models and I choose Carrier model.
She told me the price totally after tax is $8400.00, which I can pay it now or I can rent the appliances for $141.00 plus tax ($159.33).
She told me that after 5 years I can cancel the rent or I buy the appliances with its value at that time, which will be less than the price at the purchase date.
I asked: if the house is sold before 5 years what will happen? She told me there are two options:
1- the buyer accept to take the lease contract over with the same conditions, or
2- I can buy it off and in this case they will calculate how much I paid until the closing date and I have to pay the rest.

After almost 4 years (June 30 2016) I sold the house and the buyer didn't accept the lease contract, then I had to choose the second option. Then came a big surprise, Reliance registered a loan as 2nd Mortgage of $8920.77 against my house (Loan # 744551 4891042. The lawyer cut it from the price. I thought it is okay because Reliance will pay me back what I paid in 4 years (about $7650.00).
No cent, They refused to pay any cent back and they continue to withdraw $159.33 from my account automatically for 2 months after the closing, until I asked my bank to stop it.
After 3 or 4 month they send me cheque $26.55, yes believe me 26 dollars and fifty five cents. THANK YOU RELIANCE.
is this fare? the took the price twice?

I believe that Reliance have to refund me what I paid in 4 years minus reliable percentage as intrest in 4 years.

Name: Raafat Ghobrial