3rd time this year land line has stopped working after a power outage

An Xfinity tech came to the house a few months ago and did something to get the landline working again. But 6 days ago we had a power outage and the landline no longer works now. It WILL work if I plug directly into the modem, but any phones plugged into the wall jack won't work. This is the 3rd time this has happened this year. It is not the wiring inside the house. We have tried all the troubleshooting tips and cannot get it to work and can't get anyone by the phone. 

As I said before, a tech came out a few months ago when this happened last time but once the power went out we are back to the same problem.