First thing's first, open an official complaint https://www.virginmedia.com/help/complaints
The important thing about opening an official complaint is that later on if you want a refund for days without service, that you will have notified them of the problem and they can't use "we didn't know" as an excuse. Remember that all communications with forum staff, phones, emails, etc, are somewhat "unofficial" because they can claim you didn't notify them "the correct way".
In your complaint you should state what the problem is, the start of the contract, and what you want them to do to fix it (Eg: "I want a refund for the days without service due to the lack of a router")
