I'm very sorry to hear you're thinking of leaving us but I do understand giving the circumstances. You would need to call through to the team to be able to do this on 150 free from a Virgin landline or 0345 454 1111 from any other phone and our cancellations team will be able to get this arranged for you.
If you call again to cancel you should cite the recent price increases as the reason and that you're dissatisfied with this. This would allow you to cancel your VM services penalty-free while in a contract (the reason for the £120 fee quoted). I do believe you have to do this by the end of October.