"Insensitive person at reception"

I'm just over 40 weeks pregnant with my first child and have received all my antenatal care at Chelsea and Westminster Hospital, and first of all I would like to say that overall the quality of the care this far has been excellent. Although the midwives and doctors I have seen sometimes have seemed to be short of time they have been professional and nice and made me feel that I'm in good hands - a priceless feeling. Yesterday morning (27/03/2015) though, I had a bad experience at reception that I feel I have to let someone know about. I had my 40 week midwife appointment and the midwife told me to book a 41 week appointment on Thursday for a sweep, in case I don't go into labour naturally before then. When I tried to do this, the person at reception told me that there were no appointments and that I would have to call on Monday morning to see if there were any cancellations, and If there weren't any I would have to speak to a midwife. This threw me off balance a bit, and what came out of my mouth was "There aren't any appointments?". I guess I said this because I was shocked, it has never happened to me before that I've been told by a midwife to book an appointment and then not been able to do so, and also because I'm nervous at this stage of my first pregnancy and instantly felt afraid that I wouldn't be able to see a midwife. But the person at reception must have thought that my question sprung from being stupid, because with visible irritation they said "That's what I just told you", and then repeated exactly what they had said before. That was all, I had to go. I feel that their behaviour against me was insensitive, rude and unnecessary. It made me for the first time during my pregnancy leave the hospital with a bad feeling in my stomach, and it made me more nervous about this last stage of my pregnancy then I was before.