"There is not any answer at the moment, do you want to leave a message?"
Translation:Does dim ateb ar hyn o bryd, dych chi eisiau gadael neges?
Not really, and some people would use that. This sentence has in fact been deleted from the course database, so I don't think that it can be edited to allow additional or changed answers, even though it has not yet vanished from the system.
Does 'na ddim is the form used in North Wales, in the South 'Does dim' is the structure. Both mean 'there is not'