Unauthorised account access

I had a personal matter with a standard bank employees where she asked for my banking details to deposit money into my bank account. I had no knowledge she worked there. My surprise the employee logged into my account to check my financial information without authorisation. She then called me to insult me about my lack of funds and how I should present my statement and she present hers to see who's got better funds in their accounts which to me was a big shock as i expected their employees to be trained in confidentiality of people's account. I then informed the suspect about my unhappiness and without showing any remorse she continued being rude with insults about how poor I am. I trusted the bank n believed so much in them i thought there was no better bank I could deal with than standard bank. I am in a situation where I do not know if I should close my account as this is a very sensitive issue and anything can happen into my account without my knowledge. Please help as I really need a solution to this issue. I went to the bank on the 2nd of July to report the matter and nothing seems to be done about it. I went today and still there wasnt feedback as toawayforward.Disappointed