The Modem you have provided me with says that my connection is Fibre to the Node within my area. However the socket (where the old telephone connects too) is way too small for the cable that is supposidly meant to plug into and wont work.
Pullout the cable and check the socket carefully. It may have a removable insert.
Alternatively can you use the cable that was connected to your old telephone? Does it unplug from the telephone.
If neither of these then drop into a electronics store and grab a cable for a few $ (take a photo on your phone of the wall and modem sockets)