Withholding rent? what should l do?

I'm n the uk on a council estate. My neighbours who are rough to say the least have moved their relations 4 in all into a tent in their back garden their are 4 men age between 25 to 60. They are all foul mouth, do drugs and don't work, my family including 6 year old twins havent been able to use our back garden in 6 weeks. My children can't play out front as we live on a main road. Been keeping a diary and have phoned council 8 times. Their is now a 12 inch knife sticking out the bottom of the tent. Council ured me they would be removed by end of last week but they are still there. My family feel like we are living in a prison. I am considering withholding the rent but keeping it in an account any advice please please. I am suffering palpitations with the stress of it all. We are going to have to cancel our holiday as we don't feel safe leaving the house empty