As happy bunny says its a 24 hour thing.It shouldnt show up after that though.
However!If you are venting but do not like the person you have vented to, as you feel they are not a good listener,may be wait a moment,or see if other listeners are holding on,then click on vent again and you should get someone else to talk to.
Dont be turned of though as most of us are ok!If you need some one say.. a particular gender,age or experiance, I dont think there is a problem why you can't ask the listener to see if they are what you need at the time.
.If there isn't many people holding on as listeners,just leave if the same person come up again.I wouldnt have an issue if some one did this to me.
Good luck!