Not debunked at all. How do people even agree what things are worth in order to offer credit before there exists any prices?
The issue with Graeber and others is they are looking for a historical account of barter pre-dating a historical record of debt, but they will never find it, because the record-keeping begin for the purpose of recording debt. Any barter would pre-date any record keeping, and would likely be very shortly-lived before people converge onto a common money. They have completely misinterpreted Menger's 'On the Origins of Money' to begin with, and are debunking a straw-man.
> "We have actual case studies of communities developing money prices from scratch: namely, prisoners who end up using cigarettes as the common medium of exchange. [...] The prisoners certainly weren't giving each other things from their Red Cross kits as gifts or as loans. No, they first were trading (in a state of direct exchange) and cigarettes quickly became the money in their community [...] The prices (quoted in cigarettes) of various items were posted on a board. If Graeber and his colleagues stumbled upon the ruins of this P.O.W. camp, they would presumably conclude that there was never a preexisting state of barter, because they only found boards listing prices quoted in terms of cigarettes." - https://mises.org/library/have-anthropologists-overturned-me...