@cp8759The "honest mistake" was failing to set and display the clock. The bay in question is for blue badge holders but is time limited to 2 hours. At least according to the sign.
The OP is attracting attention from the CEOs because the vehicle is a liveried delivery van and the BB belongs to a child 14 years old. That's why I asked above about whose badge this was. No reason why a BB can't be used with a van but the age of the holder ferments suspicion.
Apparently the OP rents or leases the van from or through DPD. If he's not the RK then the NTO will go to the lease company and that might cause complications. Especially if another party pays the penalty and charges it back, ultimately to the OP.
It seems to me that the cleanest course of action is to submit an informal representation to try to get the PCN cancelled before Newham issue an NTO. Newham might well cancel because it involves a BB.