Something to try, if you have not already, is to speak to Kaalah-Nah
, the Chadra-Fan who stands just inside the area transition that leads to the Cantina, on the right when you come to the more open area at the end of the corridor. She (I think
) can tell you where you stand with the Exchange, and you can also bribe her to 'put in a word' for you - either that you don't like them (if that is the way your reputation is leading), or conversely that you do like them (or want to meet them, or something). That normally does enough when I'm ever stuck trying to get enough attention either way.
Hope that helps a bit!