Maybe try doing this over the phone or using Chat. The chat facility is available most business hours via the link on the update notice of the community home page.
Spell out that you don't want anything to do with the TV aspect.....
You can also try phoning the LOYALTY team. Persist despite the messages about prioritising vulnerable customers etc.
Available Monday to Friday, 10am-6pm.
Apologies for the delay.
I'm sorry you haven't been able to reach the team regarding upgrading your services. Our Loyalty Team's operating hours are from 10am-6pm, you can reach them on using one of our contact methods here https://community.talktalk.co.uk/t5/Contact-us/bd-p/tta-contact
Please let us know if you require any further help.