MUT Trade Scam

The first thing you should know is that nobody here at Answer HQ has access to your account. We cannot lock or unlock, ban or unban, credit you with any coins, or grant you any players, packs or anything else. Answer HQ is a player to player help site where users share solutions to common problems encountered while playing EA games.

Unfortunately there is nothing that EA will likely do. You arranged a trade with multiple parts which is not built into the game. The only way he would have gotten your cards is if you accepted a trade in game. The cards are gone. If you want to do multiple card trades in the future you are better off using a middleman that both sides trust and agree on. If the other guy refuses to use a middleman, he's probably trying to scam you. Middlemen can be found in many places but the official EA forums found here http://forum.ea.com/eaforum/categories/show/221.page have a system of indexed reputation threads that help you to establish whether a trader or a middleman is legit.