Ventilation Purification review: Bait and Switch 1

I called and made an appointment for the Air Duct cleaning special for $39.95. Whe the two young men arrived, one went through the house to count the vents and the other sat down with me to explain what had to be done. Work needed totaled $600.00 and a lot of 'freebies' were thrown in. I was given a sheet with questions about the work and the technicians while he was totaling up bill. Of course, I gave a good report. After they left, they had not put everything back (furniture, etc.) and had not walked me through the house to show me what had been done.
Then I checked the bill. Some items were doubled. Later I tried to put the furnace on to take the chill off the house - - the furnace will not come on. They had charged $99.95 to clean the furnace. Is this another case of 'socking it to a senior citizen?' I am over 80 and on a very limited social security