Hi Zoo,
I do DBT too.
I hear you saying that although you are very angry with your T, a large part of you does want to work through this relationship issue. This is the thing, there are things wrong on both sides. Coaching calls should be for coaching only. Relationship issues with your therapist are best talked about face to face. I think that is what she is reacting to. If you can radically accept those limits that would be better for you and respecting her limits.

However, for her, you could do the dear man and explain that sarcasm is not validating and not accepting you for who you are no matter what. It is her reacting to you. She has responsibilities to you too in DBT and although she might not be perfect at it, she does need to work towards doing it the way it is supposed to be and that includes accepting you, all of you no matter what.

You might want to talk about the calls. Calling her for reassurance is not part of DBT. I do understand your wanting to! I do understand your need. It is just not going to help you. Coaching calls are for help with life problems as well as when you feel like you might harm yourself.

Do you go to DBT group?
When you feel like calling just for reassurance, you could do some distracting, pushing away, etc.