Reliance Heating, Air Conditioning & Plumbing

So I had someone cane around my neighborhood say that they have a government program that If you house is older than 16yrs old you can get a new air conditioner.. had everything in place and then a year later I starte receiving a bill. I called and ask what is this for I was told it's for the air conditioning rental. Fine at first irt was only 56$ a month. Fast forword to 4years my bill is 85$ called then for a buy out they said I need to pay 9,586... I was floored. Why..it cost 5x times more than my Furnace and that with camebridge. I want out but I'm not paying all of that