OK, here's the position. You decide what to do as a result.
You can't cancel the account. It isn't yours. It doesn't matter that you pay the bill. All you can do is tell VM that the account holder has left the premises, and that you will now stop paying the bill. It isn't your responsibility anyway. They'll chase him, if they can find him. VM no longer offer an account transfer from one person to another.
You can apply for a new VM account. You will be send new equipment that you can install yourself but only if VM accept you as a customer after a credit check. Any email addresses you have on the old account will be lost when VM close it as they will after your "gone away" report and cancellation of the payment authority. You won't be able to re-create your personal addresses on the new account. Addresses are account linked and one-time only use.
You can move to an alternative non-VM supplier. That means one which will be using the BT Openreach network. That will only work smoothly if you have a functioning BT line installed in your home. If it needs activating your new supplier will do that for you. Most of these installations are self-install, unless you do need a new BT Openreach line when BT Openreach will come and install when your new supplier asks them to.
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