Register your complaint (preferably via e-mail so you have a record of it, Virgin like to "lose" complaints), then go here : https://www.virginmedia.com/help/dsar
Request a timescale for a response when making your complaint. Read this : https://www.virginmedia.com/content/dam/virginmedia/dotcom/images/shop/downloads/Code-of-Practice-Ap...
Ask them to adhere to point 3.
Virgin, in my experience, will not, but there's nothing to stop you calling them and asking them to add it to your complaint each time they fail to adhere to their own complaints policy.
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, and will hopefully offer you a fair resolution.
Read this to ensure the offer is fair (bear in mind it will cost Virgin money if the complaint is referred to CISAS,)
https://www.cedr.com/wp-content/uploads/2019/10/CISAS-Guide-to-compensation-for-inconvenience-and-di...
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.
