Sorry the subject was ATM rates and I was staying on that theme. You brought up interbank transfers which are managed by another organization, usually The Society for Worldwide Interbank Financial Telecommunications (SWIFT) system which powers most international money and security transfers.
By your reply your debit card is either a Mastercard or Visa who set the rates for ATM exchanges
All of my statements regarding ATM exchanges are accurate. My son works for Cirrus (owned by Mastercard) which connects all Mastercard credit, debit and prepaid cards, as well as ATM cards issued by various banks worldwide bearing the Mastercard / Maestro logo.
Visa has it's own system.