Hi my son just bought

Question

Hi my son just bought a second hand psp and bought a new game that needs the software update that comes with the new game.But we have since found out that the owner before has a non genuine update loaded and we have been told by sony that the only way to fix it so as the new software can be loaded is to give it to them so they can scrub everything .Then load the new software at a considerable cost to us[my son]Is this true or can we still load a non genuine update? thanks Andrew