What recourse do I have if a construction company did shoddy work or didn’t finish the job(s)? They refuse to return our calls.

This is exactly what your retainage is for.  The retainage is that part of the contract price that every owner retains from any contract for construction work until all work is completed and approved.  By law, an owner is required to retain at least ten percent, but your contract with your contractor can allow you to retain more.Hire another contractor to fix/finish the work the original company was hired to do.  Pay the new contractor out of the retainage.  Send the original contractor the itemization of what the new contractor had to do and what it charged you for doing it, showing you deducted that from the retainage.  Then, either send the original contractor the balance of the retainage or, if the new contractor charged more than your retainage, a bill for the difference.