They are open on the phone to haggling, or it seems like it at the time!
Heavy hint that if they cannot do better you will move elsewhere. The best you can hope for is one of their bargain contracts which must last a year to avoid penalties. I asked for another £3 less per month (nearly a year ago). No they couldn't do that but would give me a £36 discount at the start.
I still feel like someone who has "missed the boat" but I'm not sure quite how.
The service has been good and snag free. If you haven't had a shiney Home Hub yet, you will have one thrown in. "No" I couldn't have another chunk off instead of a second hub. They still sent me another hub anyway!