What do they think happened then? That you disconnected it yourself just to cause trouble?
Remind them that here has been inclement (!) weather round your way, and a lot of power lines were non-operational. It is not your fault that the landline went down, and if they couldn't find a fault, maybe they were not looking in the right place.
You pay them (right royally) for a connection, if that connection fails it is their responsibility to find the fault and put it right. The fact that they are having to reconnect it means that it was faulty. Full stop.