Send them a cease and desist communication letter. State all numbers to which you do not want for them to call anymore. You can look up these letters online and they can give you some more detail of what to include and how to format them. As for trouble traveling in the states....I would imagine it would be risky. If you get in trouble with these loans they try to make it so you can't leave the states, if I were lucky enough to get out of the states I don't think I would risk coming back in! (i mean that in a dry-humor sort of way but my numbers are very close to yours and my estimated payback is around 200k)
Good Luck!

