I have fought a similar case and won. Twice.
The first time it was actually a speed limit sign. The speed limit had dropped from 80km/h to 60km/h, but the 60km/h sign had fallen down on my side of the road, so I didn't see that the speed limit had changed. I was booked for doing 22km over the speed limit by some cops who were sitting nearby playing flash for cash. The following day I drove down the same road and saw the sign laying down on the side of the road. I took several photos and then took some screen shots of Google maps street view to show that ordinarily there is a speed sign there. I put the photos all together with my appeal and sent it off to Victoria Police (because they had issued me the ticket, I didn't receive it in the mail). A couple of weeks later I checked Fines Victoria and it showed that my fine had been withdrawn 😁
The second time it happened was a parking fine like you. I was looking for a spot in a strip of paid ticket parking in the middle of the road in Melbourne. Each spot had the spot number painted on the road in one of the corners. I saw a spot at the end of a row and it had '43' painted in the corner. It was painted faintly, but not faintly enough that I couldn't read it and everyone else was parked over their numbers, so I had nothing to compare it to. So I parked and went to the machine to buy a ticket and it kept giving me an error. I was running late for my appointment and didn't have time to play around, so after 5 minutes, I gave up and just left. I returned later to a parking fine saying I hadn't parked in a designated parking spot. I took photos of my car in the spot, then I drove out and took photos of the spot, making sure the '43' was visible. I also took photos of the sign in the middle of the section of spots I was parked in that said what zone it was so you could buy the correct ticket.
This time I cbf fighting it myself, so I employed a fixed fee lawyer. He sent the Melbourne City Council a letter telling them they were wrong and they needed to withdraw the fine and here's why... The council then wrote a very passive aggressive letter back to me basically saying that it was not a designated spot, that it was no longer meant to be used and that's why the '43' was so faint - because they'd attempted to paint over it and done a crap job of it. They knew they didn't have a leg to stand on because it did for all intents and purposes look like a valid spot still. So their letter said it was not a spot and that they would "let me off this time, but next time they won't be so understanding" as if I was a 10 year old who was being told off for not doing his homework. I just laughed and I still have the fine on my pinboard. The next time I went there they had painted over the '43' properly and even painted diagonal lines across the spot so it was clear that it wasn't a spot.
I still have the letter the lawyer sent the council if you'd like me to email it to you and you can alter it or pick bits out of it for your application for a review. Don't give in, you can fight this. My email is riffraffmama at g mail dot com.
Good luck!
