"Unacceptable wait"

I was referred to fertility clinic in April this year. After a couple of weeks ( mid May) I had an appointment with a nurse. About a week after that I received a letter that my next appointment will be in August at 4 pm. My partner and I arrived earlier ( about 3 pm) hoping we would be seen earlier as well. We had a flight later that day (9pm). Nurse said that there is a little delay. We diidn't worry about that. We knew that we have at least 2 hrs to spare. So even if we were seen by a doctor at 6 pm we would easily get the plane. About 5pm nurse said to us that there is no way we will be seen before 7pm as at the moment patients for 3pm are still waiting. This is unacceptable. I understand that there might be a delay but not 3 hours. Our next appointment is in October at 3. We will see what time we will be seen by a doctor. I understand that this clinic is very popular but there should be policy about patients that weren't seen by a doctor when it was not patients fault. We shouldn't wait that long again.

I have first signs of depression because I cannot have a child. And St Albans clinic is not helping at all.