When ask for a mediator, the text on the topic should change to like, a mediator will pm you when avaliable.
and if they try click on it again, it should say, you already asked for a mediator do you wish to cancel it? yes / no
sometimes mediater can take long to get, and people in those cases, retry is because they might think it didnt go thought, so have a better explaining function could be good, and options to cancel it