On the website it says
Maximum stay 4 hours
No return permitted within 2 hours to the car park
Meter feeding is not permitted
Ah ok, then you say you where not meter feeding (topping up) the ticket didn't print and when you tried getting another one two came out, being so close together that should work and shut them up
Sorry, I know nothing about parking legislation, but wouldn't that only work if the tickets were bought around the same time? Just thinking that most tickets show when they were purchased as well as when they expire, and presumably the lady, who gave the OP her ticket, would have bought her ticket a fair while earlier if she was already leaving