Invalid Bank Charges debited to my account

I buy a airline ticket online using my debit card from a online ticketing website skyscanner.net leading to budgetair. It was clear in the website that there are no extra charges if a debit card from Mastercard is used. I buy my air tickets on 16 July 2019 for ZAR 30545.99. The transaction is in ZAR only. Now when i check my account I see Standard Bank debiting my account for an extra ZAR 840.01 stated as bank charges. Which was not even alerted to me by the regular SMS. Please note that I a prestige customer and this happens, I wonder what should be happening with Pay As You Go customers.

Basically Standard bank is robbing their customers with the charges which are not communicated to us or we are alerted of before the transaction.