I'm up to three Parking Enforcement aka Wilson Parking waived tickets now. 

In each case I sent them a cheque for their "loss" - which is typically a couple of dollars. They always return it with a blah blah about me agreeing to their terms and conditions when I drove in, then I write back with a blah blah about not being reasonable to read their fine print then they write back saying they will take me to small claims then I write back saying see you there then they write back saying we'll waive the ticket this time but we won't next time and we usually win in small claims cases.

Same story three times - once for me, once for wife, once for a mate. They are bull*ters and can only recoup their loss from your over-parking.

Of course YMMV and IANAL

Cheers

JohnO