Recommend you try either 150 then options 1,1,4,4 from your landline if it's a Virgin landline (also works for Virgin Mobile but it's 1,1,1,4,4) then that'll put you to Retentions, or it's 0345 454 1111 but you MAY be charged depending on your call plan. Options stay as 1,1,4,4 but may be asked for account number if the automated system has no record of the number you're calling from relating to an account.
What you could also try doing is signing in to your My Virginmedia (https://my.virginmedia.com/home/index) then at the right side where your bills are under it will show contracts, if you've entered into a new one or one has been amended then it should show there with the details of it.( (https://my.virginmedia.com/my-bills/viewContract)

** I work for VirginMedia but all opinions posted here are my own.