First - Once your console is banned wait a couple days (2 or more)
Second - Call microsoft tell them that you bought a new xbox
from a pawn shop and when you went on it, it said you have been console banned
Third - They should or will ask you to give them your (profile ID) and (Console ID), found on the back of the xbox
Fourth - After that follow the next couple thing that they say and thats how you get console banned
Fifth - Soon they will tell you that they will fix it or unban it
Sixth - Never though it would be that easy right? Well try it for yourself and goodluck
Seventh - Like this to keep it running and on top!
*PS*- If they ask you how you get the GT( gamertag or profile),say it was on the hardrive that came with the xbox