The only phone numbers are 150 from a Virgin Media landline (free) or 0345 454 1111 from any other phone (call costs may apply), unfortunately.
Sounds like you might have a hardware issue but have you also checked the automated service status number 0800 561 0061 to check for any TV faults in your area?
Cancelling your direct debit is never a good idea. It never prompts a response from VM in the way you might hope for. All it does is launch VM's debt recovery processes (which are automated). This might begin with a missed payment penalty fee and can ultimately end up with default on your credit history and bailiffs at the door.
TV is not covered under the auto compensation scheme.
https://www.ofcom.org.uk/phones-and-broadband/service-quality/automatic-compensation-need-know
but it mentions above that "In addition, where signatories are not paying automatic compensation for legitimate reasons and customers are without service, customers should not be charged for a service they are not receiving."
You might reasonably expect VM to repay you the TV portion of your subscription for the duration of the fault.
A VM person should reply to your topic here and usually this can be up to a few days.