My wife parked in a council operated car park and purchased the appropriate ticket. On returning to the car within the allotted time she found the ticket had fallen off the window. Fortunately no PCN had been issued.

One month later a Notice to Owner letter arrives asking for £50 (50% increase on original PCN). We are prepared to pay any original fine as the ticket was not visible as required but not £50 as we did not receive the first parking ticket. What are our options?