Should I tell them off once and for all?!?

I dislike my in-laws!!! Very much!!! They claim to want to dish out advice, and help me with my husband's craziness but then they turn it all around and demand that he shows up at their house at night, ALONE so they can "get the other side of the story" and then proceed to bash our marriage and me. And tell him how I don't care for him, etc. I won't tolerate it anymore and have blocked their texts and phone calls on my line. Should I tell them that I am done and have washed my hands forever of them and blocked their texts/calls or should I have them guess? My husband is angry that I did it, but his line is untouched so he can still talk to the looney birds. I want NO relationship with these people. How can I let them know I won't tolerate their behavior anymore?