I have just had the same issue, someone quit aganist me yet... ive been banned!
Actually, even premium members get banned when they get caught.
I have a slow internet, how would that put me in this fair play [language - MOD]?
The automated system flags things it considers suspicious. Frequently disconnecting and reconnecting is, if I understand correctly, something that it picks up on. However, that can happen innocently if you have a bad internet connection.
If you contact the support team, they may be able to help you: https://support.chess.com/customer/portal/emails/new
How the hell did I get a fair play violation when I won the friggen game and didn't say a word in the entire thing?
ridiculous.