There is no typo, the adjudicator has given the council 4 weeks to respond. That being the case, I suggest you make a representation now to protect your position.
I will PM you some links to put in the representation, they will redirect to here (https://drive.google.com/file/d/1qzv2oCy5ldrsZU_2GUZdrP9yMU2fELmh/view?usp=drive_link) and here (https://drive.google.com/file/d/1tMbwa26GHgp56B7IUatsn5JXZu89NQF0/view?usp=drive_link) but if you give them the links I'll PM you, we can use the click count to confirm whether they've looked at them or not (obviously do not click on the links I PM you as we want the click count to remain at zero). If they don't click on them, we can then prove they've failed to consider all of the evidence. If they say in the rejection that they've considered all the evidence, we've got them for lying as well.
Dear London Borough of Redbridge,
I rely on my informal representations as my formal representations. I further refer you to the documents at LINK1 and LINK2.
Yours faithfully,
Tick "The alleged contravention did not occur", here's some draft text:
Dear London Borough of Redbridge,
The alleged contravention did not occur. Signage on this road indicates that footway parking is permitted, and as far as I have been able to establish the footway parking ban was lifted from Wards Road at some point in 2014; it follows that a contravention of this sort cannot occur on this road. The PCN must therefore be cancelled.
Yours faithfully,
The council will definitely reject, but you have good chances at the tribunal stage. I'll help you with the tribunal appeal if need be.