I'm looking for advice on how to go about suing someone for services not performed for work they did (actually didn't) do at my dental office.

I hired an IT guy who was recommended to me by a friend to try and fix some network and other issues I was having with the computers at my dental office. I was not as involved as I should have been with tracking his progress ( or lack thereof in this case) so I wasn't aware of the atrociously exorbitant amount of money he was billing my business while not fixing any of my problems. Once I finally caught wind of this, we had already paid him over $250,000 and not one of my issues had been solved. As far as I'm concerned, anyone who could bilk that much money out of someone without producing anything at all is a thief. How do I go about getting that money back. The whole ordeal since I made that discovery has been extremely jarring for my entire family and I intend to include damages in my suit because of it,.