Hi @eddy0612,
Welcome back to our Community Forums! Than you for your post and I'm very sorry to hear that your emergency contact is having some issues with their mobile services after switching from Virgin Mobile to O2.
However, we you're not the account holder, we can only advise basic checks, as we would need the account holder to reach out. However, we the account holder of the mobile that's experiencing issues is no longer with Virgin Mobile, we would advise them to reach out to the O2 team on 0344 809 0202 to take a look at their Contact page to see how else they can get in touch.
There's also their troubleshooting help page that you can take a look at to see if this can assist further.
As they're no longer a Virgin Mobile customer, we would be very limited as to what we can do to help as we'd only be able to assist with their former account.
Please keep us updated on how you get on and if you need any further help.
Thank you.