FNB has refused provide a reason

I discovered in June 2015 that it is possible for FNB to transfer money from my account without notification. I sent the mail below to the premier banker assigned to me and to date, an explanation has not been provided.<br> Hi there,<br> I need to say that the service i have had on my account has been much less than complimentary over the last three months. <br> I complained that someone physically went into my account and transferred funds from my main account and i am yet to understand why. This was since June 2015. Also in July, my account was debited with 644 rands without any notification. I would like to know what this debit is for and why i was not notified that a payment was required before the transaction was loaded against my account. It would only be very fair for FNB to let me know what i am paying for and when such payments are due rather than for the bank to just try and collect funds without any notice. Today 1000r was transferred also without any notification. A few months back, i paid funds into this account and immediately the bank's system took the funds as payment for a debit order which was only due after two days. The bank says there was no record of this in the system