How do I end the battle with overbearing MIL & keep everyone happy?

Yesterday MIL & I had our first major argument in 8 years. long story short, I have made it clear that I no longer want her daughter (SIL) in my home or around my child. This girl has done everything from file false charges with CPS to bringing drugs into my home as well a drug dealer & getting busted with cocaine in my car. Its been a constant battle for 8 yrs & I am done. Yestderay my MIL comes to pick up my 4 yr old for her weekly overnight & I look out to see the SIL in her car. Of course I blow up. We have recently moved & I made it clear that I didnt not just want her in my house...I didnt want her to know where we lived. The argument got very heated... I reluctantly let my child go bc she was soo upset but told MIL after this day never again or visits will end. I was ready to talk things out until I am informed that MIL took my child today 2 c SIL & husband who I also hate. MIL told my hub she knew id be mad but oh well..Ending visits hurts my kid more than ne one but what 2 do