Theft cabin luggage!

Very disappointed with Mango airlines. My cabin luggage was taken from me on boarding a flight as I was informed that the cabin is full. The cabin was in fact empty and there was enough space for my cabin luggage. My lock was ****** and bag tampered with! I Reported this theft to Mango desk and I was told very directly there is nothing Mango can do! No recourse for this theft! Disgusting! #369613 reference of luggage