FNB INTENTIONALLY DROWNING ME IN DEBT??

Been a roller coaster ride with this bank at my 2nd stint with them, have this account for a good 2 years however things started going south around December 22. Crazy how my account is just slipping away from me and when I call to find out I am not really getting a straight answer as to what is increasing the limits that I intentionally set knowing my affordability, do not get me started with the call centers and the bot of FNB. I am now sitting on a R3192.76 overdrawn account, that was sitting on R472.23 overdrawn amount 2 days earlier, most amazing thing I have ever seen - especially in a month that I intentionally freed about R5000.00 from the previous month. How does it get to escalate this much? My understanding is that if there is no money in the account there is no money, how does it get to be overdrawn? The requirement for overdraft on the account is set to R1000.00, this is a requirement if you upgrade to this account. Logic, well, my little logic dictates that if there is R50.00 in the account then that is it, how do I now get charged R200.00? I need someone to explain this to me, I cannot afford to go to a branch, if explanation still does not make sense as has been the case, let us switch my many accounts with FNB to a different bank. Guess the many eggs in one basket are coming back to bite me in the behind.