I don't have an issue with paying for parking - I'm quite happy to pay for parking and to pay more for bigger spaces better security etc. What I disagree with is having to pay for parking that I'm not going to use as is always the case with pay-and-display.
If, say I know I'm going to be 30 minutes, and 30 minutes costs 50p, but I only have £1, I have to pay a pound and get no change - WHY? If I leave the car park to get the correct change, I'm likely to get fined!
If I don't know how long I'm going to stay, inevitably I always have to pay for longer than I need with no chance of recouperating the costs that I've paid for a service that is not going to be provided!
Why can't I reclaim cash for the excess time that I'm not going to use, or re-use the ticket next time I return to the same car park!
To me, the pay-and-display system as it stands is very much biased in favour of the car parks. I wouldn't be difficult to introduce machines that give change and to have a system where you can scan your ticket and get a refund for the unused time!