This car runs a multiplexed / CAN - BUS ( CAN - CAN on later 307s ) electrical system, it does have a fuel cut off switch BUT it computer controlled, you the owner CANNOT reset it, it needs to either go to a Peugeot main dealer or someone with the correct equipment to reset it.
To trip the fuel cutoff switch on one of these it must have had a hell of a smack.
It also could be a immobiliser problem, it really needs to be plugged in & the BSI scanned for whats wrong, without that information your waisting your time & money.
Lee, June 2007