Ex Girlfriend has moved out and account is in her name. Can't contact her now to switch/cancel account

Anyone else had this issue. I have contacted my ex-partner but they don't know any of the details to the account anymore and don't care as it's my bank details attached to the account. I have tried ordering another virgin media broadband account, but it cannot be installed as there's another "active line". I have cancelled the previous direct debit to try and nudge virgin media to cancel the previous account but they keep saying they can't do anything as the previous account is still active even though no money is being taken for it. Please help