How did I not see this one? OK... here's the scoop. When a spam thread is deleted, you can delete all posts and ban the user as well. You choose the message and then select "delete as spam" and then you're given a whole bunch of options. Makes it SO much easier to get rid of the spam and the spammer all in one easy shot.
Regarding unlocked cells... why can't you unlock yours? If it's GSM you should be able to get codes... especially if you tell your carrier you're traveling internationally.