Posted this the other day, and they've just gone and dropped a fiver off a month, plus added £25 to the value of the cashcard. I've had to cancel and re-apply.
Go through Topcashback to BT
Get the BT Unlimited Infinity 1 for £29.99 a month with a £59.99 activation fee
You get £80 topcashback (£90 Quidco.... but i prefer TCB, more reliable for me)
You also get a £150 pre loaded cash card to spend wherever
Works out at effectively £15.83 over a 12 month contract, for unlimited fibre broadband, including line rental and weekend calls, caller ID, nuiscance calls blocked, and free BT sport for 3 months (just a fiver to use on app/chromecast after that). That's less than most places charge for just line rental.
Yes... the topcashback isn't guaranteed, but for me it's always been very reliable with a good claim process int he small chance that it doesn't work.