Ah well, guess I'll have to pay up then... thanks for your thoughts

Hi all, I got a fixed penalty notice for parking in a disabled space but before I get totally slagged off it was one of 6 spaces - all disabled - outside a charity shop into which I was dropping off some donated goods. I didn't even lock my car because I popped in with the bags and when I came out the ticket warden was there with the ticket. On the notice it said car observed from 13.47 to 13.47. I have challenged it for this reason but they just said its a contravention and pay up but I feel that the warden could have just said to me (she must have seen me get the bags out the boot and go in the shop) and the fact that there is nowhere for non-disabled people to park when just dropping off charity goods is a bit discriminatory anyway. Any thoughts please?