TalkTalk are serially dishonest
A current example of their blatant dishonesty is come contract renewal time. Their website T&C's state that new subscriber deals are available to new and existing customers who have less than 90 days remanining on their existing contract, but try renewing on one, you can't. The live chat drones will deny all knowledge of the deal you're trying to get even though it'll be up on the website. Their usual pitch is just to say "It's not on my system" or that deal just expired and offer you some other deal (I've just spoken to my manager bull...).
After I had this experience I spoke to two others who had the exact same experience, apparently a hot topic on the forums too so not random one-offs.