Regardless of whether the beneficiary somehow accessed the account, it remains that the Rep Payee was the party responsible for the account's activity. If you are going to file a ChexSystems report, list the Rep Payee, not the beneficiary.
Going forward, review your bank's procedures on issuing cards for Rep Payee accounts. Ensure that you will not issue a card to the beneficiary in such situations. If you find that you must issue a card to a Rep Payee, do so only after making it clear that it is not to be used by the beneficiary.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8