TBH a broadband contract doesn't end just like that, it's an initial fixed term and the contract itself simply continues once that fixed term ends (unless you take out another plan).
You still have to actually cancel the contract once the fixed term has ended.
Virgin want 30 days notice, even once you are out of your fixed contract term:
https://www.virginmedia.com/help/vir...-how-to-cancel
From - 1. You may be charged if you’re leaving within your contracted period
If you do cancel with them then I suggest that you cancel any Direct Debit at your bank as well.If you're on a 30 day rolling contract or you decide to leave us after your minimum fixed term contract period, you'll just need to give us 30 days' notice.
That stops them just keeping taking money once your 30 days cancellation period has ended. (And most phone and broadband providers are known for doing that).