Mario Balotelli said on Wednesday that he will repay Italy coach Cesare Prandelli\'s faith in him at Euro 2012 and that he was fed up of being told he has to grow up. Prandelli has included the 21-year-old Manchester City striker in his preliminary squad for the tournament in Ukraine and Poland despite a series of bizarre off-field antics and his dire disciplinary record. \"Prandelli has waited for me and I can\'t wait to pay him back,\" Balotelli told reporters at Italy\'s training camp near Florence. \"The European championships are the opportunity of a lifetime... \"I\'m fed up of being told I have to grow up, it\'s not true. If I have to grow, its tactically and technically\". Balotelli also deflated speculation he would sign for AC Milan in the close season or return to his former club Inter Milan, saying he wanted to stay at City.