Disgusting service from Nedbank

I was informed via an SMS that my internet banking had been suspended as a result of suspicious activity. I was given a phone number to contact which I did and was calmly told that a 5 digit amount had been taken off my account. Apparently they tried to get hold of me telephonically. but couldn't. Well, I received no message that such an amount would come off my account, I was not asked to verify or confirm the transaction, nothing. They see it is suspicious, but they let it go through, seriously??? I then get told that an investigator would get in touch with me - this has not happened, so I record everything on an email to their suggested email address <***>, and what do I get? An automated response telling me that they are busy. You've got to be joking. You watch money being ****** off my account, for me a very sizeable amount, and this is how you treat customers. You disgust me and I want ZA people to know about this absolutely pathetic service level of yours - it is shocking and I must insist that I be reimbursed for your failure to safeguard my money in your bank!