Bad FNB Response to *****

On 14 May 2024 money went out of me acc. it was from Fspl Technical Service. The matter was reported to my bank the same day. I stop my cart and remove my FNB abb. i went to Klara Glenn FNB and report the matter to them in the branch. Fnb sent an email to me stated that the matter was declined. I never got the email. I saw the mail for the first time in the branch on the 10 June 2024. The bank notifies me that the transaction was legal but can't give me proof that it happens. it was case ***. all they told me that it was done via transaction ***. How must i just except that over R6k is out of my acc and they do not give me good explanation. I feel my money is not safe at FNB. Can someone help me to resolve the matter? Regards Martin