I lived in 2 different countries recently. The Air Force was nice enough to send us.
I in NO WAY could have learned enough Arabic to speak to someone. Not in person, not on the phone, nothing. There were no classes for me to take. I did some Rosetta Stone, but other than about 100 words, I spoke no Arabic.
When we moved to Belgium, I was lucky because I'd already taken a few years of French. I can tell you that it did not prepare me to speak on the phone. I can get by in person, but on the phone it is very very difficult.
Thank goodness I met such *nice* people there who were kind to me since I was such a piece of crap for moving there and not learning an entire language ASAP.
I'm sure in all of your travels around the world and away from Michigan, you've known all the languages of the countries you've lived in, though.
ETA: Your boss shouldn't have hired people who don't speak English if she was going to have trouble communicating with them and if they were going to have to deal with the English speaking customers, so I can't really feel badly for her.