They never returned, but weirdly, the phones did. Just be grateful you can use them to call for help now.
- Find the Antenna before using the Telephone, in Blackfield Station.
- Find Jerry Cans to fill the generator and use the Telephone, in Farmhouse.
- Hold down "X" to use the Telephone.
- At times the Telephone won't work even though you're holding the phone. To fix this unequip the phone then equip it again. If it's still broken have someone else try and make the call.
- Farmhouse's Telephone equivalent is an older variant of a phone, using a rotary dial.
- Blackfield Station's Telephone is a free model that can be found here.