Hello good people of dis (especially the one who said he worked for CAB)

Ok, so I moved out of my flat in the middle of August, and the Landlord has been really evasive about giving us our deposit back, shouting us down, avoiding our calls, claiming he can't give it to us without a letter from us, then refusing to give us his home address so we can't send the letter, etc. etc. And now we've finally tracked him down, he's deducting £50 each (£200 in total) for cleaning. We left that flat much much cleaner than it was when we moved in, and besides, what cleaner costs £200? He legally had 30 days to pay us the money, which we all really need, and I just don't know what to do to get it back. HELP!!