Yes, terminate immediately. Crayon kiddies had a fabulous response. You don't need to put in your contract that if you fear for your safety that your contract is over. Document EVERYTHING in case they do take you to small claims court. People like this tend to be too busy bullying other people to bother with a law suit.
Without the abusive part, this sounds a family I'm terming - complaints about everything and renegotiating my contract repeatedly to fit their life. I put up with it for 9 LONG months. Next time, will save myself the headache and terminate the first time someone is blatantly disrespectful. Life is too short to put up with turkeys on a daily basis.