@ssok: My advice would be to make the installer perform to specification.

(I am not a lawyer -- this is not advice -- see a lawyer).

You should have had a "scope of work" as part of your installation contract. Hold that up in front of them and say, "Either you perform to these specs or we will get legal on your backside."

Try talking to the owner of the company that did the install, if you cannot get satisfaction from the salesman and the technician. Document precisely what impact this has on your company, including, if possible, lost business. As a last resort, you may need to take the installer to court.

Forcing these less-than-professional installers to perform as promised is good for the industry. You'd be doing us all a favor to help these guys decide that this is the wrong business to be in if they're not going to be professional.