It seems awfully haphazard and sloppy,
I rarely disagree with John, but feel he is being far too charitable in this particular analysis... As the representative payee has absolutely no claim to the funds it's nothing short of moronic for an SSA employee to say the original representative payee can do anything he wants with them...
What a former representative payee would do would depend on why the fiduciary relationship ended; e.g. if it ended because the person entitled to the benefit died, then the funds would be payable to the decedent's estate. If it ended because a new representative payee was appointed, the funds would be payable to the new representative payee, acting in that capacity. A representative payee has no rights of survivorship.