Do you mean the credit card charging a fee, or the current account?
While I know you are charged a fee for withdrawing money from a credit card, where you are getting a cash advance, I wasn't aware that they charged a fee for withdrawing money that you already had in it.
From their website (highlighting by me.)
What are the cash advance fees for withdrawing cash from my credit card?
The cash withdrawal fee is €2.54 or 1.5% (whichever is greater).
You can avoid cash advance fees if your credit card account is in credit when the transaction hits the account or if it has a zero balance after the transaction is completed.