Well, you probably got burned which sucks. But next time don't ever pay a general contractor 1/2 down.... ever. The contractor should get paid based on a draw schedule, based on key milestones of completion. They should be hitting you up with invoices over time to pay the labor & materials for the completed subcontracted work.
The only subcontracted work I've paid 1/2 down on are cabinets and deposits for countertops from Lowe's and etc.
If they simply bid $x.00/sqft for the total project, you'd have a similar set up with well-defined milestones for pay upon completion of that part of the total remodel/new construction.
*Always leave cash on the table in case they happen to go MIA as well. Never give them all but say... $500.00 before overall completion. Keep 1,000's.
If you've reached out to him and he hasn't died of Covid or something, I would at least blow him up on all of your local facebook pages (if he's from that area) to warn others.