So my first theory didnt work but Ive thought of a new one which will reset your routers cache and request for a new ip address from your ISP provider which in theory should unban you from the BO2 servers.
1.Go to your computer and open up cmd prompt
2.Type in ipconfig /flushdns(Push enter and wait)
3.After that ipconfig /release(Push enter and wait)
4.Then last type ipconfig /renew(Push enter and wait)
5.Now your done and it might take a day to get the new ip address from your ISP
Please let me know if this works!