The thing to do assuming you stay, is at the end of the deal term or minimum term, whichever is the longer, first try for a decent retention deal, though those now seem hard to get - they were ridiculously easy and cheap in the past, and if you can't then switch your phone to Pulse8 like I and jelv and I think some others did.
It sends the broadband cost up a bit when you take the phone away. £2.50 on FTTC and £2.50-£3.50 it seems on ADSLx. Though if you have signed up to a bundle, as you have, it's £2.50. It's joining on ADSLx without their phone service on a minimum term contract that gets the £3.50. I suspect that is a website error.
Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site -
www.robertos.me.uk. Domains, site and mail hosting -
Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs -
IPv4 &
IPv6