He's missed the 14-day discount therefore whether it's re-offered by the authority is in their hands.
Get apologetic reps submitted IMO.
He feels like the fleet team will use that against him and not pay the charges...
This is not their choice. They cannot pass the buck under parking regs, the buck stops with them(this is 'owner'* liability, not driver).
Which could add another layer of complexity..is the company actually the registered keeper or is the vehicle leased? If the latter then the lease company would get the NTO.