Advice Needed re Parking Fine

Got a notice today saying I have to pay a $329 parking fine issued by the courts (or something like that) immediately or my car will be deregistered.
It was the first time I'd heard anything about it.
Apparantley on the 28th of September last year the Prospect Council say I was parked over a yellow line.
Ive looked back on the date and it was banner making night and I know for a fact I was one of the first there and didn't drink that night so remember quite clearly parking in a legal car park (there was a choice of hundreds!). Add to the fact I never park illegally as people who do peeve me off no end.
No notice was left on the car, no contact until today.
Obviously I don't want the car deregistered and the money isn't a huge amount but I feel pretty aggrieved about the situation.
Only complication is that we salary packaged our car so prior notice MAY have been sent to our employer which didn't get passed on.
Any advice on what I should do?
It was the first time I'd heard anything about it.

Apparantley on the 28th of September last year the Prospect Council say I was parked over a yellow line.
Ive looked back on the date and it was banner making night and I know for a fact I was one of the first there and didn't drink that night so remember quite clearly parking in a legal car park (there was a choice of hundreds!). Add to the fact I never park illegally as people who do peeve me off no end.
No notice was left on the car, no contact until today.
Obviously I don't want the car deregistered and the money isn't a huge amount but I feel pretty aggrieved about the situation.
Only complication is that we salary packaged our car so prior notice MAY have been sent to our employer which didn't get passed on.
Any advice on what I should do?