I can't understand why you've been told an all day appointment, it's either AM or PM, they have never done all day appointments
tbh I think it's terrible you've been send round in circles, this should have been sorted out on the first call

One big thing we were told, when I worked there, was to take ownership of calls and make sure the query was sorted there and then.
I think you're gonna have to bite the bullet and call to find out what's going on but I can see a big disappointment as I'm guessing that no-one has been booked at all for you....