I work in hotel so I often have to manage complaints of upset guests. My main problem is with guests that don't speak very well english or have particulary accents. My English is not very well so I panic when I see a foreign guest shouting to me.
Did you ever had this situation? How did you have manage it?
my department is the same as you, and this's one of the reasons i learn english to deal with this type of situations :)
just be confident and try to make your conversation short and simple between the guest , plus on that you have to listen to songs and watch movies with different accent to improve you listening skills, this will help you to deal with any guest with different accent.
i hope i helped ^^