My benefits have been stopped

Hi I am a single parent with three dependents! My last child is under the age of two, however, all my benefits have been stopped; child tax including nursery fees! Working tax and my housing benefit! Firstly the problem started when I was on maternity leave and I claim housing benefit last year, it took them months to sort out my entitlements then when I went back to work! they stopped my housing benefit again and took months to sort out my ellegibilties! I went back and forth to the housing trying to sort it out and and then once it was sorted they stopped it last month. I have been pressured to send in my wage slips and now the want bank statements! I have provided them with the relevant information they have requested for the past 13 Months and they still keep stopping My benefits.  In April I received a letter from inland revenue asking me why I made a single claim if I ain't single! I called them and explain to them that I was! They ask me to provide them with all my house hold agreements including my bank statements so I did! And they still closed my claim! And I am now not getting any working child tax! My daughter can not go nursery therefore I can't go work! I called them again and they said they want proof of where my last child's dad lives to sort out my claim! I explain to them on the phone that him and his mother had a falling out and he asked me of he could use my address as a correspondence address until he got himself permenant address! He is at present down has homeless with the Birmingham city council and has been for a few years he does spend at least two to three nights at his mothers home and has his mail going to her house for correspondence purposes!