If LX charged your credit card in EUR you will get the same EUR amount back. If your credit card issuer converted the charge from HUF to EUR, obviously you will get a smaller amount back in EUR now.
From the credit card statement it should be clear in which currency a charge is hitting the card.
If LX refunds in HUF, you have a good chargeback case against your LX. You are entitled to a full refund, not a refund in a different currency.