Request every single bit of data possible, from the start of the contract until now - they are obliged to adhere to your request.
This will likely trigger a call from the DSAR team looking to resolve the complaint with you to avoid doing the work of collating your data. Hopefully they can resolve this for you. If that doesn't occur, you can refer the complaint to CISAS after Virgin fail to adhere to the 8 week timescale, and they will likely compensate you for your inconvenience and distress.
'they will likely compensate you for your inconvenience and distress'
no. that is not standard protocol. i've worked with and against different ombudsman. you don't even know what their complaint is about. stop giving false information when you do not know anything at all about their complaint. for all you know they don't like the colour of the V6 box.
IF the ombudsman deem compensation is due then they will get it. But many complaints even in the customer favour do not automatically trigger compensation.
they don't even attempt to adhere to it. if you had ever tried to pursue a complaint with Virgin (i have done so multiple times and received compensation) you would understand. i had to re-open my last complaint 3 times as they kept closing it due to "inactivity" (they did not send me a final response letter, as requested). their problem is they have an extremely limited complaints department that ignore offshore callcentres notes (all they can do to register a complaint is include it in notes that go nowhere, the staff have told me as such when i queried the lack of responses). this is a structural failing, hence why i am confident what i said is factual; any basic complaint will escalate to result in compensation as Virgin do not respond to complaints.