Without meaning to be picky, I just noticed that despite the website suggests so at multiple locations, the phone support wasn't available today until 10pm - all I got was it's available until 9pm on weekdays'. Maybe worth an update?
(I tried 150 and the 08.. number. Links: https://www.bt.com/help/contact-bt/account-and-billing/broadband and https://www.bt.com/help/contact-bt/orders-and-upgrades/existing-customer/broadband/order-upgrade)
Thanks for reading/best!