If your T is not responding to you, you need to get another T! That is not schema therapy! Schema therapy is about you recognizing (not practicing) that when people in your real world, not your therapist, do not call you back or miss an appointment that it is not about you or an abandonment of you. You are paying your therapist to engage with you; if your therapist is saying it is part of the way she is treating you to deliberately make promises and then break them; I would not want that kind of therapy.

You do "enough" to check why a therapist did not get back to you "this" time but if they keep having incidents where they are not reliable(!!!) then you don't want them as a therapist anymore than you want a parent who abandons you!