@nottscraig I've cancelled the DD, as they're not taking £64.00 from me that is not due,
I'd strongly recommend you reinstate the DD ASAP, and then check to make sure the bill is paid on time even if you want to dispute the amount.
Let me give you a flavour of what happens when a customer stops a direct debit for a service that has a credit element. I'm basing this on experience at other large companies with similar scale customer service operations. On the day following the expected payment that you've stopped, somebody in VM gets a file containing all failed DD payments from the previous day's payment run. They don't ask "why has the customer not paid?", they don't think "maybe there's a problem?", they just put this list into the "overdue" process, and add on a late payment surcharge. You will get a call, email or letter asking you to contact VM and pay by card, and your credit history will be stained with an overdue marker. If a month later you've not contacted them and paid then this usually becomes a separate "arrears" process. In law overdue and arrears are the same thing, for companies they often denote consecutive parts of the overall debt management processes. Note that phoning and complaining that you'll pay when they sort out your grievance is totally irrelevant to the process. The offshore oiks that are VM's first line customer service won't give a ****. With debt in arrears, then you may get two to four weeks grace, but at the end of that without payment or a repayment agreement being established, they'll cut off your services, and your credit record gets a "defaulted payment under credit agreement" marker. But that's still not the end of it. The owed money, plus late payment charges becomes a potentially bad debt. Companies don't like walking away from money they're owed. So they'll start to issue more threatening letters, inviting you to pay the now larger balance to avoid court proceedings or debt collection agencies (some combine this with the earlier demand for payment). If you still don't pay, typically they won't bother with court (other companies sometimes will) but they'll pass it on to a contracted debt collection agency, who'll add their own charges to the amount owed. But these "first tier" DCAs are often a bit lazy as its relatively easy pickings, so you might manage to dodge them. VM (if they behave like other companies) will then factor the still unpaid debtors file to other debt collection agencies. If you still evade those, then VM will parcel your debt up with all the other bad debtors into a package of owed money of several hundred thousand pounds, and sell the debt on to debt purchase company. These are usually a different debt collection company who buy the legal rights to the debt for a fraction of its face value. That company has the greatest motive to hound you to the ends of the known universe, because they'll have paid perhaps 1p for every pound you owe, and they get to keep everything the collect. These companies can be resourceful and relentless, tracking you through social media, other credit history data, electoral roll data and a range of other methods. Maybe you'll get away with it? Imagine the dementors from Harry Potter - they're on your case and they want to drag you and your wallet to Azkerban. Even so, you might be able to avoid paying, who knows, and this is probably six-eight months out from the date of the first stopped direct debit...but we're still not finished. Your credit history will by now have more skidmarks than Brands Hatch, and will be visible to potential lenders (mortgages, loans, credit cards), as well as service providers (other ISPs, water, gas, leccy, mobile phones etc), plus large employers and prospective landlords for the next six years.
Really, honestly, don't stop your direct debit, the only person who will lose is you.