You still can use it.  I wrote an article on it on my site.  To sum up that long article, all you need to do is go to the opposite carrier than the phone was meant for.  If your phone model shows M919 it is tmobile so you can use it guaranteed on H20 or any ATT prepaid service like AIO.  I know this for a fact because i am imei banned myself and use it on h20.  That article i posted about this matter geta tons of visitors daily who are obviously IMEI banned or tricked into buying phone om craigslist.   http://techlivewire.com/1645/what-to-do-when-your-phone-imei-is-t-mobile-blacklisted.html

Btw they are saying all carriers will combine renegade device database so soon people may not hop aroumd carriers on imei banned phones but then again that will mean lost business for carriers that drop imei banned phones from other carriers so who knows where this will go.

Whatever you do, dont flash another samsung imei as some people do.  You will lose 4G and it is a crime but this is evilzone so do what u like.