You would therefore need to contact the VM Faults team on 150 from a Virgin landline, or 0345 454 1111, options 1,1 and 2 (Faults) but best to call at 8am to avoid call queues it will probably be a box swap, however the agent will also be able to check if you need an engineer visit.
When calling Faults you will get the automated response asking you to press 1 for the link to online support, perform tests, reboot etc. Ignore the options and don't press any buttons then you should be placed into a queue and an agent should pick up the phone and resolve the problem.
Dave
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali