I've experienced a similar thing except I could never trace back the reasoning to my ban. I had hundreds of hours and a lot of money invested in the game and was forced to start fresh. Sadly DE doesn't have a very good support system (as most games don't) in responding to why an account may be banned. Although it may suck that most developers don't care for why you're are banned it's not special to just DE. I suggest just creating a new account and starting fresh. After thousands of hours into my new account, I'm glad I didn't leave the game.