non Deposit payment

All what I want is my Deposit back. They can't tell me that I didn't give them the full month. I first spoke to their Building Manager Peter that if they are going to be charging me water 739+ then I can't afford living in their very small flat. End of June I told him that I need to move and ask me to resend my Documents again and I sent it to him on the 27th June and he didnt do anything about it. On the 6th July I followed up with him,to my surprise he just said that I must send and notifications via online. Now their company are refusing to give my money back that I didn't give them the full month. I left their flat on the 1st August and I left electricity for over R150 in that same flat. I just need my Deposit back and I don't owe them anything.