Crooked estate agent?

I have been leasing a semi in Johannesburg since October 2006. I was in-between jobs earlier this year and have fallen a month and a half behind on my rent. The estate agent sent me a final notice, but the amount is about double as to what I say I owe. I do not receive monthly statements and when I asked for a total recon on my rent account I was told to come to their offices. I am temporary employed and paid per hour, so any time I take off, I don't get paid for. I previous had a similar experience with the same issue. After I managed to pay the account up to date (on the figure given by them), I all of a sudden had a credit balance of nearly R1500. Is this estate agents doing me in and where can I find help? I feel they are trying to do me in and as a single parent and sole breadwinner for a family of six, I do not have the full amount they are asking for and they are now threatening me with eviction.

Send a letter to the agent asking for a reckoning of the account. Detail what you see as your debt, and ask for clarification as to how much you owe and why. Indicate your willingness to pay what you owe. Send this by some method that gives you a receipt when they receive it. Keep a copy for your records. Do this immediately so you can reach an agreement before this leads to an eviction.

Also, read through your rental contract and see if there is any mention of late fees or penalties.