"Appointment difficulties"

So you are sent a letter to see a specialist, after waiting weeks, when you get there, at your hospital do you go straight in, NO, you're waiting ages i have up to 45mins, so why do they put 3-30pm, on your letter, because when you get there, there are 4 more with the same time!? who is at fault here the person who types those letters out, to send to your home address, it is not the specialists fault,