If Aegean Airlines charged you unexpected baggage fees at the gate even though you followed their baggage policy, you have reason to challenge it.
First, gather your boarding pass, baggage-tag receipt and photos or measurements proving that your baggage met Aegean’s size/weight limits.
According to Aegean’s baggage policy, fees apply only if baggage exceeds the free allowance for your fare class or is declared as extra/overweight.
Then contact Aegean via their official customer-service or online contact form, explain that your baggage conformed to the allowed allowance for your fare class, and request a refund of the charged fee.
Mention that you are aware that gate fees should only apply if the baggage exceeded allowance or was not prepaid — and you complied.
If they refuse, consider writing a formal complaint on Xolvie to seek a resolution.

