Re: verbal abuse from a teacher
I agree with the rest of the folks here - get out.
The "other" dojo that has a variety of instructors is a good thing. They're allowed (asked?) by the chief instructor to teach, so the technique must be consistent enough to be recognizable within the dojo. Learning from a variety of sensei is a good thing - there's more than one 'way' to twist a wrist.
If, after seeing all the responses of those above, you haven't gotten out yet, get out, now. Go to the other dojo - or stay away from Aikido for a month or so and then go to the other dojo. Make no announcements, just stop showing up. If called "Sorry, I'm not going to the dojo any more."
you aren't obliged to say why, to justify your departure, or anything, just get the (&%*&$ out of there.
If phoned and the abusive language starts - say "Stop phoning, good bye." and hang up. Persistent calling? Restraining order. Still persists? Others may have a better handle on what to do...