I see the FUP is 100GB but weird they advertise it as 5GB package
You missed
the Unlimited package. That's the 100GB one.
The broadband is "White Label" BT Wholesale. Like Orange now is and Vodafone used to be. The PO is just a sales front. But I hadn't realised the price.
You could try
vivaciti Family 30 which is cheaper and a monthly contract. Similar also available from Aquiss, ADSL24 and xilo/uno, I'll leave you to research those. Best to use their checkers, as the more attractive packages aren't available to you, with there being no LLU or even ADSL2+ at your exchange.
As I said, you can keep your phone with BT if you wish, with all of these.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - Plusnet Value Fibre.
"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~