Family Fresh United Broke my furnace during "cleaning" Vancouver Washington

I hired this company after receiving a coupon in the mail. They came in and scared me by telling me about all the things wrong with my vents and showed me gross pictures of what inside my vents supposedly look like. I was so freaked out that I hired them. It ended up costing $2400 (a huge difference from the $59 coupon I had)!!!!

AND when they left, they left my furnace running and it just blew cold air. I called later that day to report the problem (left a voicemail), I called again the next day leaving another voicemail and then had to call again the next day to finally reach someone! My furnace no longer works, when it did before they touched it. All I want is my money back so I can hire someone else to come fix the damage they caused! The manager (who was super rude by the way) acted like he was doing my a favor by offering to refund $100 out of the $2400. They are refusing me a refund because they believe that they completed the services BUT they also broke my furnace so that it no longer blows warn air and then didn't take or return my calls for several days.