Yes, this would annoy me tremendously and would definitely have me looking for a new therapist. You seem to have been very clear and reasonable in communicating what you wanted, expected, and needed from her in terms of scheduling, so her actions seem pretty strange. If she's working psychodynamically, a standing weekly appointment is standard--and even if it weren't, it's what you asked for. It almost sounds like she's refusing to block off her evening appointments consistently so that she can use them to bring in new clients, and is pulling a weird bait and switch without regard for how that lack of consistency impacts people.