@fttboy in the circumstances, I would write a representation inviting the authority to exercise its discretion by cancelling three of the PCNs, and allowing you to pay one at the discounted rate.
In order to force them to take a wholistic view, this should be done in a letter to be sent by post (if you challenge them online, they'll inevitably be dealt with individually, which we don't want).
As the PCN requires you to use pages 3 & 4 of the PCN to make a challenge by post, you'll have to send (all in one envelope):
1) The form on pages 3 & 5 of each PCN, duly completed and signed, and in the "representations" box just write "
see attached letter"
2) The letter you are going to write.
There is a possibility that they might accept and cancel a couple of the PCNs.
There is also a possibility that they might ignore the representation for some of the PCNs and just issue a charge certificate, which would then give you grounds to file a statutory declaration and then pursue the case at the tribunal for failure to consider (which would be an open-and-shut win).
If you go down this route, I would recommend going to the postbox with all the paperwork, films the various pages so that the PCN numbers on the form are visible, film the letter, film yourself putting all the pages in the envelope, sealing the envelope and posting it. That way, if the council considers representations for some of the PCNs but not others, they can't dispute that you did in fact make representations.
In the first instance I suggest you write a draft based on the arguments of proportionality and put it on here for review.
