Guess ill pay twice. Supplier is owed more than I owe. Contractor was researched ahead of time. Contractor has been paid mote than material cost already. I am not going to get *** raped and walk away with a smile that's for sure. Why doesn't supplier put a lien on contractors stuff.
I think your best course of action is to contact the supplier and let them know what happened and that you have already paid the contractor more than he owes the supplier and you are withholding the remainder until the job is done. Clearly you agreed to pay part up-front and withhold the remainder until the job is complete. If the job is not complete, the remainder will not be paid.
Alternatively, you could go out and get estimates to have it fixed (if you haven't already) and pay the remainder less the cost to have it fixed and then you either let the original contractor fix it and you'll pay that amount or hire somebody else to fix it.
In either case, it seems you paid for the job, not time and materials, so if the job isn't done as agreed, you shouldn't be obligated to make full payment.
FWIW, I doubt that BBB or Angie's List will do much for you. Your best ammunition is probably word of mouth, at least where I live. If somebody asks you about your concrete work, just be sure to let them know who did it and what a douche they were. Angie's list seems like a joke to me, I'm not going to pay for a service that I might use once or twice a year at the most, and the people who are are probably not looking for the same contractors (I want someone I can work with, not a turn-key operation) that I am or just signed up to post a bad review about a bad situation.
