Invasion of privacy

I logged into my account to make my monthly eft payments. I noticed that one of my beneficiaries, WHO I PAY EVERY MONTH, is no longer on my list. I speak to my grandfather and he tells me that he has the same problem and went to the bank to sort this out. ABSA told him that ABSA went into various bank accounts and deleted beneficiaries as THEY felt there were too many. NOW PLEASE EXPLAIN TO ME HOW YOU THOUGHT YOU HAD THE RIGHT TO GO INTO MY ACCOUNT AND DELETE DETAILS WITHOUT MY PERMISSION. I AM CONSULTING WITH MY ATTORNEY TO CONFIRM IF THIS IS LEGAL WHICH I HIGHLY DOUBT. How dare you go into my account without my permission and delete my beneficiaries. I pay them every month now I have to go and obtain all those details again etc.