I want my deposit

I moved out on the 1st August and as per my contract it states that i will be given my deposit on the 15th day after moving out, Thando the agent i was dealing with tells me she is not in the office and will not be paying my deposit any time soon with that said their contract states that with every late payment they will charge R150 per day so since im waiting for my deposit it is only fair that i also charge them R150 per day whilst waiting for me deposit. They got a new tenant to replace the unit by they are telling me i must wait for my deposit from the owner but i have been paying rent to them and not the owner of place how is that fair.