Just renewed my contract with TalkTalk fixed for 18months.
Phoned up to cancel and was given and mazing deal, new customers can also try it.
I got broadband and line rental, with free super router delivered, also was offered free Sim with 200 mins and 500mb data, unlimited texts.
Also the Sim is for as long as I remain with them even after 18months, the Sim remains free.
If you are looking for cheap contract no harm in asking even if you not a customer, and topcashback.
If you take in to account the Sim it works out less than £15.00 a month.