Hmm, strange. You should have a new dialog option with either of the two pilots on your left when you enter the Cantina on Korriban if you have agreed to meet Mekel later. Did you use cheats or KSE? A player had a similar problem and it turned out that he used KSE to change many things and my mod didn't seem to like it.
You could try to open your savegame (but don't forget a backup copy) with KSE or Kotor Tool and look for the global variable "mekel_waits". If you find it, change it to "1", then the dialog option with the pilots should be available. If not, I guess there was a problem with the waiting-script that should set the variable. You can send me your save and I'll try to fix it.