Theft, *****, No Proof!!

On the 2nd May I had realized that I had an amount taken off my account of R1800.00 I never received any notice SMS nothing I was then concerned being a Public Holiday obviously the banks were closed! SO the next day I went to the bank and apparently it has been taken OFF for bank charges?. The lady at the Bank said there is nothing she could do?. So I called customer complaints and in doing so spending more money! which I got the same response nobody can help. I then typed an email to ABSA asking that someone calls me to resolve the issue still until today nothing!! I want to know where did I sign or any proof as agreed upon that you are allowed to take money out of my account without informing me?. You say the money is for debit orders that rejected?. So why do you take the R1800.00 OFF my account before my debit orders for the month have gone OFF which then makes them bounce again , which in return you will charge me for again???? How does that make any sense??????? You CANNOT just do as you please!! and this has to be resolved!! OR else I will take this further!! Warwick Barltrop ***