Almost exactly the same thing happened to me (also in the UK), except rather than checking me in, they had transposed a couple digits on my NHS number and check

Almost exactly the same thing happened to me (also in the UK), except rather than checking me in, they had transposed a couple digits on my NHS number and checked in a random person. Not sure if the NHS number has a check digit, and if not why not, but I digress... Rather than going to lunch, after I sat waiting for 3hrs they closed the department. When I went up to let them know I hadn't been seen yet, they apologised profusely, called back the specialist - who had already left - and saw me after closing time.