EA defines coin distribution as:
• buy Coins
• sell Coins
• use auto-buyers or other unofficial clients
• farm Coins
• make false claims
• use someone else’s account
• use multiple accounts to boost your performance in-game
• use bots in or abuse the Auction House
• cheat in-game
• promote, encourage, or take part in any prohibited activity described in section 6 of our User Agreement.
I can adamantly say I did none of these things, and was still banned for seemingly no reason.