Disappointed to find out that Virgin do not have the option of WiFi phone calling. Where I live is a network black hole almost, regardless of the network, and WiFi calling would have made my life a lot easier.
My wife and daughter have Huawei phones via EE which can be call enabled. Will have to seriously think of swapping to a different direct network when my contract ends, unless Virgin do something about it in the meantime
This isn't the answer you are looking for, but there are workarounds such as using facebook messenger or whatsapp. There may be other apps you can use as well. They will both work on mobile data as well as wifi.
I realise that the previous conversation took place a while back but perhaps the answer is not correct as this article (link below) actually guides you simply through making a few changes in your Virgin Media router settings to enable you to benefit from EE’s WiFi Calling facility. It states that it is only because of the default router settings that you cannot initially obtain WiFi Calling so definitely worth reading.
I've used the same settings as in that article to mend broken WiFi calling on a few Virgin routers, but for the benefit of the thread...
This is for where the Virgin WiFi router is preventing EE/Vodafone/etc WiFi calling from working. In other words, where the WiFi connection is through a Virgin router, NOT where the phone is a Virgin Mobile one.