Originally Posted by
tfar
Instead if you say: "Excuse me, I need a cab to the airport. Would you be so kind to call me one, please?", that should never get a strange look and should always be fulfilled. It's part of being a helpful human and part of being a professional.
If calling taxis is not part of the person's duties, then even this phrasing could appear demeaning. It suggests you think it is and that the person behind the desk is a gofor who is there to do your bidding. Projecting a sense of entitlement is probably not going to do you any favours.
On the other hand, if you ask for advice (how can I get a taxi?), then that is flattering. It implies that the person you are asking is knowledgeable and in a position of superiority in that situation. In that situation, they are much more likely to (a) want to demonstrate their knowledge and (b) offer assistance to someone in need.