Please do not cut off the payments. I know it seems like the best thing to do however what you do not realise is that virginmedia report to credit reference agencies whether you pay or not.
Miss a payment it will show as a failed payment on your credit report.
Miss 3 payments chances are you will not get an overdraft increase, a credit card, perhaps a mobile phone contract, a mortgage etc. Also every missed payment will affect the rate you are offered on a loan, overdraft etc.
Believe me it's not worth messing up your credit over a firm dispute like this. You're better to just argue via the formal channels until virginmedia provide written agreement that they'll allow you out of the contract.
I'm trying my best to help

but ofc it's ultimately your choice.