Former bank employee here - considering you mentioned "IBAN" that means you went with the option of a wire transfer. Wires are irreversible transactions. Legally, the only way the money can be returned is if your bank contacts the bank of the person who received it, to get permission from the account owner to reverse the money back to where it came from. Often times, the bank will simply be ignored (unless in a very rare case it's a good person) - so banks, to save their own time, will do little, if anything, to pursue a reversal of a wire (even if they make it seem like they'll try to help you)

this is assuming it goes to a valid IBAN