Poor customer service

I went through a process where i made a payment to somebody claiming to a legitimate business to buy engines from even spoke on whatsapp with the person and after payment was made of 7600 over to them they never delivered as promised i immediately that evening went to FNB telling them that i have been ****med and if they can please assist in stopping the transaction or help me in anyway as it wasnt even 24 hours after payment was made that i found proof i had been ****med. The recipient status on my fnb the reflected "recipient not paid" after logging the ***** on the App with the bank. I went into bank the next morning, they told me i need to log a case with SAPS which i immediately did and then revertted back to them,being the bank. I had emailed all proof and conversations and everything i had to the bank and they said they will assist yet everytime they still send me follow up emails and ask to send what they have requested instead of helping me.. and everytime i go onto the fnb chat onto the app i have re explain the whole story again to get some sort of assistance and keep being sent from pillar to post explaining everything, no feedback just asking to re explain everything and sent the proof ive been providing for 8 weeks,, im very disappointed in the service im getting from FNB as being a long time customer with them.. i gave them everything to be able to assist in the case and yet it seems like its going nowhere in them trying to assist me as their customer..