Hellenic bank charges EUR 15 for SEPA transfers!

I made a SEPA payment to a 3rd account at Hellenic Bank Cyprus. The currency was EURO, the sending account was in EURO and the recipient account was in EURO. Hellenic Bank deducted a charge of EUR 15! I make many SEPA transfers and it is not normal for charges to be incurred. In fact, this is one of the benefits of the single currency. I have tried to contact Hellenic, but they hide behind GDPR protection - I don't hold the account with them. As the 3rd party was able to pass on the charge to me, they suffered no loss, so have no interest in raising a dispute. The bank is therefore able to levy the charge with absolutely no risk or accountability. I will certainly never be transferring money to an account at Hellenic Bank again.