This can happen with faulty wiring. Plug your new phone in, using the phone cable that came with it, as close to the Master Socket (where the phone and broadband come into your property) as possible. Ideally into it with nothing else connected at all, but if you need to use any supplied broadband filter, then do so. Have the broadband side, the router etc., disconnected, so the phone is the only thing on the line.
Ring it from your mobile. Can you now hear it ringing? If not, pick up the phone anyway, and see if you can hear yourself from your mobile.
If you could hear it ringing, connect the router back up, let it settle down, and then ring yourself again.
If it is now ringing, than you have an internal wiring fault between the Master Socket and where you normally position your phone. And this is your responsibility if you own the property, or your landlord’s if you are renting.
But if it didn’t ring in any or all of the above tests, get on to NowTV Broadband support, using the phone number they will have given you, and report the fault.
NowTV Broadband customers can ring NowTV, about broadband issues only, on the contact number they can find in My Account/Orders & appointments.
See the posting above yours for the answer.
Broadband belongs to an address, so if you have moved home without contacting NowTV to move your broadband to that new address, you don’t have it any more.
However, whoever moved in there will be enjoying ‘free’ broadband (to them) that you are still paying for.
If you go to My Account/Broadband & calls, and look up ‘moving home’ you should find the phone number you need.