Technial service calls should always go to an America location with native-American speakers. The modem should have an on-off switch.

Suggest you get a surge suppressor with a switch. I have computer, printer, modem and router connected to it. One strong surge can cause lots of damage.  BTW, many of the "Representatives" are American. I recently found a college grad that can't write or do math. Said "I only learned how to use a calculator or computer to do that". "Beam me up Scottie, there's no intelligent life down here"!