Just because they aren't plugged in makes no odds to VM - if you've still got them, VM will charge you.
When did you first try to get these removed from your account? If you gave clear instructions and VM's agents failed to process them, then you are reasonably entitled to a refund from that data, and compensation for the fact that the company failed to deal with this despite the repeated contacts to which you refer. Let's put a value of £100 on the compensation, and then however many months at £28.50 a month. What does that add up to?
Next up, would you stay if VM arranged to collect the boxes, and paid compensation? If the answer is yes, then forum staff have one chance to get this right and arrange a settlement as above. I'll flag this for forum staff to take a look and see if they can assist. Anything less than generous and consider the steps below.
If the answer is no, you've had enough and want to cancel, then so long as you're not in a fixed term discounted contract raise a formal complaint now (there's an online form in My Virgin Media), asking for both the settlement above and cancellation of all services within 30 days, and request that all communication about this is by post, not email or phone. Keep a copy of the responses you'll get, and dial your expectations down to "a response so poor that it is an insult". This is not in the hope of VM settling because complaint handling is very poor, but it is a requirement before taking the matter to the industry complaints scheme CISAS. Potentially VM will do half of this (the cancellation) but not offer a settlement, sometimes they'll do neither. Sometimes the complaints just disappear.
If you get a great response, all well and good. If you get completely fobbed off, or only a partial settlement, then respond to the "resolution" by asking for a deadlock letter, which you then use to formally escalate the matter to CISAS (without a deadlock letter you can still use CISAS, but have to wait eight weeks from the initial complaint). If taking the matter to CISAS, explain in as much detail as you can the background to complaint, your attempts to resolve it, and the outcome you now want. If you have to take the matter to CISAS, then also do a short summary complaint to Ofcom - they don't get involved, but they'll pressure VM on any poor complaint handling.
