無効な賭けに勝ちました

I played a bet I won I was credited to my account 581 euros and after a few minutes they made it back to bet22. They found an excuse that I knew the outcome of the event. What do I do in this case?

Έπαιξα ένα στοίχημα κέρδισα μου πιστώθηκαν στον λογαριασμό μου 581 ευρώ και μετα απο κάποια λεπτά το κάναν επιστροφή στην bet22. Βρήκαν δικαιολογία πως ήξερα την έκβαση του γεγονότος . Τι κάνω σε αυτήν την περίπτωση ;

Hello.

Although sports betting is not my strongest side, I'd say the casino maybe got some information that the game was manipulated or they can possibly have some issues with the way you place your bets. Anyway, I would strongly recommend further communication with this casino.

Which casino do you bet in, please?

I'd say that's the main point why people do sports betting. They try to guess the final result.