Duct Blasters

They showed up 25 minutes late.
When removing my screen window, to bring their lines through, the tech couldn't figure out how to take the screen out. he began bending the screen so i had to intervene.
i put some filters across some of the vents as an interim measure as the ducts were filthy when i moved into the house. instead of taking 10 seconds to pull them out, the tech instead blasted the first one down the duct work where it inevitably became stuck.
They drilled extra holes in my duct work near the furnace to blast compressed air, instead of using the existing ones.
When i quizzed the tech, his response was 'the more holes the better'. then he proceeded to drill holes in spots that he could not utilize properly afterward, which seemed even more foolish.
when servicing my furnace, the blower was reinstalled poorly so that the bottom cover on the furnace would not close/seal properly. I noticed it as the furnace whistled loudly once the weather turned cold and i turned it on. I could hear it from the second level, while my furnace is in the basement behind a closed door. Obviously it was quite loud.
I never had this problem before they serviced it.
I called and someone was supposed to return to help figure out why the furnace was whistling so loudly, but never did. I eventually adjusted things myself, which seemed to improve things a bit.
Also when they re-installed caps in the duct work where the holes were drilled, some of the caps were popping out before they even left.
When i asked them to tape them up, they tried to blame it on the companies that serviced the furnace in prior years stating that they must have drilled the holes too large for the caps. However I never had this problem until they serviced the furnace and I think the cause was more related to how they bent the duct work around these holes with their tools.
They complained about running late because I made them put tape across the holes, but an hour earlier they were trying to sell me an extra service to clean my fireplace. How would they have had the time?
They failed to leave a sticker on the furnace indicating the service date. I've asked twice if they could send one in the mail, but have received nothing in over a month.
On a positive note, the ducts are a lot cleaner.