A grumpy old man

Some would say not a surprise but today I am particularly so. I went to the hospital to pick up my mother - I always object to paying to visit hospitals but my mother said that one get twenty minutes free. 
She was safely picked up and I went to the car park machine to validate my machine. £2 - so I must have been over the twenty minutes. Of course the machine did not take old £1 coins which was all I had. A quick visit to the booth with two attendants and they had no change. A credit card however did the job.
I then looked at the ticket as in the blip and saw that in fact I'd only been 16 minutes so back to the helpful duo in the booth. Presumably they could give me the £2 back. 
Oh no - once it is paid then that is it was the response. What you have to do is just present the ticket at the exit without validating it. 
Obvious really. Presumably then what you are meant to do is set a stop watch when you pick up the ticket and then if under 20 minutes, don't pay and go the exit otherwise pay. 
What a daft system that I have never seen before. You could think that this system is trying to get more cash out of the car park as the notice saying a free 20 minutes was not exactly spotlit. I also note that their time keeping is not great - the ticket says I left a minute before I paid......
My sister came over in the evening with a meal and much lamb was eaten. A relatively early night as tomorrow is a 4:30 am start.