atari2600land

It's entirely a cost issue. Native speakers of English demand a high starting salary (i.e. above minimum wage). The less the job pays, the more limited are the communication skills of the person doing it. As their language skills improve, they advance to better jobs. 

But sometimes wouldn't you have to spend more to run things more efficiently, offsetting the spending more with the savings you get when things are run smoothly?

I do not disagree with your assessment, but this has been my experience over the past two decades. I have no idea if there is any measure of potential revenue lost (in the private sector, at least) because of limited/non-existent customer service. Since it has a monopoly, Government is obviously less concerned with losing customers.  

One quick story: Some years ago, KFC was heavily promoting a new type of chicken sandwich. I went to my local restaurant to order one. The cashier had utterly no idea what I was asking about, so I directed his attention to the HUGE advertising poster hanging directly behind him. He was completely unaware of this new product. Now, I do not know if it was a language barrier, poor training, or some combination of other factors, but customer service was definitely impacted, and the store lost the potential revenue from my purchase that day. (That establishment closed just a few years later.)