noooo service virgin active

I had a contract there in dec 2021 to June 2022 and I cancelled the contract in june 2022 and NEVER heard from them again . noooo contact ! yesterday when a collection company phoned me 3x did I phone there headoffice and after 2 days only got to soeak to somebody I owe them money!So what is my rights and I had a month to month contract!