********** bank transaction

I am a standard bank customer, a transaction was done on my account on the 23rd January 2019, I received an sms to confirm the transaction, however this transaction was not done or authorized by me,I then received a call followed by an sms notification stating that my account has been suspended as the matter was still investigated, I again on the same day went to the branch to lodge a complain against the matter and again stating that the transaction was **********, I was advised that the matter will be investigated, and that they will come back to me after 72 hours which they did not honor as I am the one who had to call them , however it came to my attention that the transaction went through on Friday the 25th January 2019, this however is after I had reported that I am not aware of the transaction, the standard bank consultants were rude and kept on accusing me that I am the one who gave away my personal details to the recipient of the transaction. I called them today (28-01-2019) and I was told that the matter has been closed and they will not reverse the transaction, my concern is the nature on how they handled my case, the consultants who showed no interest to assist me, and how did these people get my banking details which are private and I trust the bank with my money.