This happend to me a couple of weeks ago jim. Your broadband is ok but the landline isn't working. https://my.virginmedia.com/faults/service-status should be your first port of call and should tell you if VM is aware of any faults. Just enter your postcode and landline number. You can also run a test on your equipment if you sign in.
It can take a while for the mods on here to get round to sorting something out. That suggests that it may be your phone that's the problem (I have a lot of ancient wires throughout the house and a broken but working phone connected) and you should try this self help stuff (it goes round the houses). It may also be that it's something simple that you've missed. That is the second port of call. HTH.
I've had several phones that just stopped working for no apparent reason. On closer inspection some of the metal connectors had gone rusty, or the copper based ones had oxidised (gone greeny blue, the copper equivalent of rust). They were only cheap ones, but they did the job.