This guide shows where to cancel Virgin Plus (Mobility / Internet/TV) in Canada, with links to official sources.
Virgin Plus provides Member Care phone numbers (and 611 from a Virgin Plus phone) and offers a request-a-call option.
If you are ending a term agreement early, their support content notes there may be early cancellation fees depending on your contract.
If you have internet/TV equipment, confirm how to return the modem/receiver (if applicable) and keep tracking/receipts.