i been suspended for selling an account

hi i sold my playstation account since i moved from ps4 to Xbox one but i did not know that i was not allowed to. But my gameflip account has been suspended for fraudulent or suspicious activity and they said they sent me a warning but i have received no warning at all from them so i did not know that it was forbidden to do so.
Account Code: LSELPQ

I checked your case and unsuspended your account. Please, do not relist more of these items.