Mmm... As you say, I don't really care where the call is from, if it's efficient!
The trouble is not on the poor chai wallah (to cite Slumdogs), but on the efficency of some of those outsurced services that sometimes outsources to family on the other side of the street (or whatever)!

It happens that we had to sell a flat, the buyer, though he had the money, wanted a credit line, called his bank for it, they asked for some papers send to an insurance company, etc.
 After a few days the insurance said some paper were missing, so he send the complement to them.. Still his bank said it wasn't a deal because paperwork as not proper, now the insurance asked for the first set of paper he had sent in the beginning...

To make it short, he discovered after a while (one month late in buying proposals), that the outsourced company had open three different folders, one for each of his sending, and as each was incomplete, they sent mails to the bank for the missing paperwork...

He finally got everything straightened, but spent quite some time to achieve the feat...!

On a personal note, when I have phone sellers for window frames (latest fashion for annoying phone calls in Paris) and I have the very slight telltale of accent, I answer in Hindi... Nice pause at the other end and a quick end of call :-)

"What can I do, What can I write, Against the fall of Night". A.E. Housman