First please accept my deepest thanks for taking time to respond.
So I managed to get internet back and you are spot on to ask the question about the hub / router. I am suing a TPlink archer m600 model. It had lost the profile somehow. Please don't ask how this happened as I was using the internet one minute and the next minute it was gone.
When I logged in to the router I saw it was having a Vodafone profile. I was a bit sceptical but left it. Several rounds of reboots later, I thought I am going to try the profile settings on my phone ( which also has a virgin sim). Google for the profile settings as well and they seem to match and added a virgin profile.
It started working again. I will post here the URLs of the pages which had these profile settings as well. Thanks again for responding. Hugely appreciated.
Please note that Virgin doesn't publish a support email address / no chat function or even a twitter handle to contact anyone. It's a disgrace in that sense.It's all good as long as it works. when it breaks you are on your own. Thankfully, we also have sky broadband so it wasn't the end of the world. Just imagine if that wasn't the case.