"Rescheduling ultrasound appointments"

I received a letter for my fetal anomaly scan which I had to reschedule. The letter gives two number. One of which is an answering service number so not useful. The other number rang out on different days that I called it. No answer. Ended up calling midwife centre who then called LCTC only to tell me that the centre was shut today so I should call tomorrow and see if I can change appointment then. I also called yesterday (Monday) and no answer, so not sure if they were open then either. No information on the website regarding opening/closure times and nothing on the letter either.

It seems that it would make sense to inform patients when is the right time and days to call to prevent the wasting of patient and midwife time in trying to sort out a simple rescheduling of an appointment.