"Poor appointments' service"

I was referred for an ultrasound, by my GP at the beginning of May. This was in the context of a cardiac A & E admission a couple of weeks earlier. I heard nothing. Ringing today  —I left it two weeks—I am told that UHL radiology is not yet 'releasing' June appointments, they are not made until next week, just a few days before June starts. I was advised to ring back next week. This is hardly an appointment service worth the name - looked at from the point of view of a patient, or this patient in particular. I feel frustrated and annoyed, and incredulous. Why is the so-called service run like this? (I am a wholehearted supporter of the NHS).