Give it a day or two to see if the forum team can get this ironed out, as that's quickest and easiest for all concerned.
If they can't sort it out, raise a formal complaint with VM using the online form in My Virgin Media asking that they cancel/refund any charges intended or made, failing which you require a deadlock letter for the purposes of taking the matter to the industry complaints scheme, CISAS. In the meanwhile VM will probably go ahead and add a £30 or so "Non-returned equipment charge" to your next bill. Let that go through, you're going to get the money back eventually, and if VM aren't careful they'll be clobbered for the significant costs of a CISAS review.
Possibly the VM complaint will be properly considered and they'll cancel the charge, but don't get your hopes up, VM's complaint handling is very poor. If they fob you off, close the complaint, reject it, then you use the deadlock letter to take the matter up with CISAS, asking for a settlement of refund of any charge, plus compensation for the inconvenience and distress. You can't complain to CISAS unless you have already complained to VM, and then you either have to have a deadlock letter, or alternatively you have to allow eight weeks from the date of your complaint.
