"Andy, could you explain me please, what whould be happen, if my ring generator is blowing their exchange equipment instead of their generator."

Don't quite understand what you're saying there.
Do you mean you can't see why it's a problem when you apply ringing voltage (which, BTW, is on the order of 70VAC on top of the 48V DC bias), but not when they apply ringing?

The reason for this is that the phone company uses a switch to disconnect its sensitive input circuits while applying ringing.

"but it looks like they are protected even from this"
Well, the seatbelts and airbag(s) in your car are there for your protection, but you don't go deliberately driving straight into brick walls at speed, do you!?