BSNL Telephone — my 74 years parents in village are harrassed by line man babusingh

sir, my village phone no.[protected]. my parents who are over 74 years old live alone there.we pay our bill regularly and there is no due.
i am living in kolkata very far from my native place, every time in a month or two our phone goes dead.
when ever our driver goes and complaints the person name babusingh at complaint centre wants my father to meet him.
when ever my father goes to meet he shouts at him saying why is he sending the driver for fault booking
as i said my parents are very old they need telephone service and we trust bsnl hence took the service but this is regularly happening since last two years the same person babusingh reply rudely without respecting old age people what to do?