F* FNB

So my account went into an overdraft situation and I'm really upset because I paid the amount that my account had in the negative BUT at first it was R390. So I paid R250 and then R500 into my account. I had only R202 LEFT after R750 was paid into my account, NOW it still says that my balance is -R290. How in the WORLD is that possible?? Firstly I lost +-R548. How can my account STILL be in the negative if you already took R548, which was more than what was supposed to go out in the first place?

I'm really tired of banks and their bull****!