"Parking charge of £85.00"

I had to take my son to Trowbridge A&E a few weeks ago and in the last few days I have received a parking charge of £85.00! I called the hospital who informed me that they have a new parking permit service in place where you have to register your reg plate at reception - this came into place last October, I do understand this may be something that needs to be done what Makes me angry is if this is something that has only really came into force why couldnt the receptionist of informed me of this especially when I got to the reception to book my son in to see a doctor ? Being that you don't just go to the hospital for fun and it's normally under quite a stressful situation then I do believe a thoughtful reminder from the receptionist would of been a lot nicer then recieving such letter through the post . Not happy at all about this and I will be appealling it .