Wallace Mechanical

This company now goes by a different name, and I will update, as soon as I get the name again. This company is very scandalous and unethical. They installed a HVAC unit and they made an OBVIOUS mistake and installed the concentric vents backwards. Our unit started malfunctioning recently and so we called another co. And they informed us of Wallace's mistake. I called Wallace Mechanical, only to be told by a very rude employee that Wallace went out of business and they would not come out to rectify THEIR MISTAKE, and there was nothing I could do about it because the old company went out of business and the new company was not responsible for those mistakes. Here's the clincher: The new owner has the same last name as the old owner, so if you own a business and it goes bad, transfer ownership to let's say your wife and you won't be responsible for your mistakes. Very, very UNETHICAL.
And is it a wonder the "old" company went out of business if they made such obvious mistakes? The choice is yours, but I wouldn't trust them to install it for free.