If the arbitration was done in accord with state laws that permit the judicial enforcement of an arbitration award, it's usually pretty simple to reduce the award to a judgment. The judgment can then be enforced judicially, with garnishments and execution against assets as permitted by law.

A new judgment arising from the arbitration award can be expected to appear as a new entry.

You can offer whatever settlement you want, and see what they say.

If you want to know the legality of what they've done, take all of the documentation including the arbitration award to a lawyer, and have your lawyer review it. They may be acting improperly, but we have no way to determine that.