So what can I do? It seems its the parking authorities fault for sending out the request for details even though the ticket was paid within the time limit. But they are hardly going to pay my $30 for me, are they?

The ticket I received specifically said that if I paid within 10 calender days, no request would be sent to the registered keeper of the vehicle.

I complied with this 100%, but they've sent one anyway and now I'm facing a bill?