False advertising

In April I got a call from the ***** DEPT about an international merchant transaction, which I told the consultant that is was unauthorized as I didn’t authorize that transaction. I was told to go to the branch and complete a statement of disputes and I went to Benmore branch and completed the form. The consultant said I’ll only get the feedback in about a month or so. When I finally queried the prestige Dept about my dispute I was told that they can’t find the form and now Benmore branch is closed. Besides the form that’s missing I have a problem with Standard Bank false advertising their services if you can notice suspicious transactions and call customers to confirm but still let the transaction go through, that is false advertising cause what’s the use of confirming if the transaction is authorized or not and still let it go through and why would the bank authorize a transaction while there is insufficient funds in the account?? The last time I check if there isn’t sufficient funds the card will decline how was this transaction let though resulting in my credit card overdrawn for an unauthorized transaction????