Thanks for using the forums to get this issue with your question answered, I am sorry to hear you're having trouble getting through to the retentions team.
We won't be able to cancel or renew your account from here, however here's some info I think will be useful -
Are you out of contract? If you're still within the minimum period of your contract you could be liable for EDF's or Early Disconnection Fees, so think about this beforehand if you're wanting to cancel!
The best and quickest way to cancel or renew is to call our retentions team as early as 8am in the mornings as this is our quietest time. Their number and options are 0345 454 1111, option 1, 4 then 4 again. Their job is to save customers from leaving so they will offer you a deal that may suit your needs, but if it doesn't float your goat 🐐 you can request to disconnect in 30 days.
Here's a link to some further information on our website about your contract and and if you want to cancel - Renewals and cancellations
I hope this helps and I wish you luck in your ventures!