How to update link after using data.preventDefault

I'm using the following code to call a couple of functions which do ajax post. I found by not using data.preventDefault the functions seem to get triggered multiple times so I used data.preventDefault which fixed this. I just can't work out how to update the links once the functions have run.

$(document).bind('flagGlobalBeforeLinkUpdate', function(event, data) {
  if (data.flagName == 'event_attend' && data.flagStatus == 'flagged') {
    data.preventDefault = true;
    postAttend();
  }
  if (data.flagName == 'event_attend' && data.flagStatus == 'unflagged') {
    data.preventDefault = true;
    postNotattend();
  }
});