same thing happened to me in Orpington, also a Ringo set up. Said I'd tried to pay, then a few days later send copy of phone bill, call shown but no parking charges. Letter crossed with this saying pay up. I hadn't understood about having to put your debit card details in, and had assumed it was charged to my phone bill. So down to me. Anyhow when I went to pay the ticket on line, they had in fact cancelled it. Best of luck.