Thank you all for sharing your similar experiences and frustrations. I have collected so many similar tales here and on local Facebook groups that I am convinced something needs to change and WBC cannot keep turning a blind eye to this. I'd encourage others to stand their ground as well so that the adjudicator will see the extent of the problem.
I provided good evidence with my appeal that I had e-mailed the parking queries inbox and sent a message to Wandsworth Council via Facebook when I was trying to renew 3 hours after the expiry of my 'grace period'. All that evidence has all been ignored and a standard 'tough luck' rejection letter sent. At this point I don't really care if the fine is £55 or £110, but I do want this to stop for other people's sake - even if all I achieve is to get Wandsworth to send an e-mail to all residents to tell them to start keeping track of their own renewal date because their own system is flawed. Annoyingly I used to keep a record of the date when I first moved here from Lambeth, but got out of the habit because the reminder system worked so well!
I raised a Freedom of Information request back on the 12th October to try and find out how much money the council has made from fines to residents whose permits have lapsed. Sadly it took 17 days to get an acknowledgement e-mail from the FOI department so not sure how long it will take. If anyone else wants to ask for information the e-mail address is firstname.lastname@example.org