Are statutes in Louisiana that require a GC to notify subs of any used retainage before the contracted return date?

We have not worked for a particular contractor for 2 years, the contracted time to have retainage released (their contract that we signed), so we routinely sent a letter asking for the return of our retainage. The contractor now denies he withheld any retainage from us and has conveniently manufactured a $5,500 "advance" payment for a job that he says we owe him. We never invoice for any work that is not completed. And I find it highly interesting that this "advance payment" record has no check number on it like all his other payments to us. He is now demanding $5,500 from us after zero contact for two years. I would have noticed if we were paid an extra $5,500 unattached to an invoice. It always took an act of God just to get a check from him for jobs we HAD completed.