@Tizzy902 - You have to send in a Support Ticket. Tap the little gear icon in the upper lefthand corner of the home screen in game. Then tap Support. There's a number of options. Search for the appropriate section, and be as detailed as possible. The 'report' button only pertains to Global Chat, and it's supposed to be used when people are abusing the chat room. However, that button won't help in the case of cheating.
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http://kabam.force.com/PKB/KbContactUsForm