"Great staff but..."

The services provided by Machen Eye Unit are very good and staff are lovely. However, I've been extremely frustrated recently as I have an eye surgery to do and they keep cancelling in the last minute. I understand they might have a list of priority, but if that's the case, I think they should just say it, or tell the patients they will get in touch when they have availability. The surgery has been cancelled twice in a row, and they literally called me 2h before the appointment time. The reason was the same: the machine has broken. Really? What a coincidence, I must be very unlucky as the machine broke on the specific dates they booked me in. I planned to have the day off, and they gave me very short notice twice. I wonder now if I'll have this surgery done. It's just really frustrating. As I said, I wouldn't mind if in my first appointment the doctor had informed me the hospital is very busy and they would call me when they have a date. But the expectation is what frustrates me and short notice.