contact 8 more.
and be sure to tell them over the phone that you will only have a qualified HVAC contractor come to your home.
tell them you must have a load calc done properly according to Manual J and the ductwork must be sized properly according to Manual D.
Then you should be able to weed out the hacks before they get to your door.
I fully support the military and the War on Terrorism.
If you don't know, then don't do. If you don't know and still do, then be prepared to pay someone else a lot to undo what you did and then do it right.
If you do know, then do. But do it right. Otherwise, you may not be doing it long.