Jeri, with respect, if you're dealing with a VINDICTIVE person, there are very few ways of dealing with it sanely. It sounds as if this person is quite willing to cut off his/her nose to spite his/her face. He/she is quite willing to lose a perfectly good listening venue because he/she can't have his/her way.
I've worked in places where quadriplegic friends have allowed themselves and their wheelchairs to be carried up two flights of stairs to my gig, and then back down again afterwards.
I don't think the person involved here is quite willing to do that.

Seamus