This doesn't surprise me at all. In an error of judgment, I used to be a Talktalk customer and received what was euphemistically called a "welcome call" from them shortly after signing up. During that call, I was treated to the hard sell to upgrade my standard broadband to fibre, and told a number of untruths as part of the process: in particular, the operator told me that it was almost certain that during the course of my 12 month contract the quality of the service would deteriorate to the degree that it would become completely unusable due to the age of the lines serving my property and that fibre might become unavailable in the future so if I didn't upgrade then and there I could be left months and months without usable broadband.
Needless to say I complained to TalkTalk about their using misleading customers with a view to making a transactional decision that they would not otherwise have, which is a breach of UK consumer protection law. Naturally TalkTalk chronically mishandled the complaint and even went as far as to claim that the call was not a marketing call, despite it being almost 30 minutes of trying to sell me things.
Ultimately, I took the matter to CIFAS who agreed with me that TalkTalk engaged in banned practices including 'bait and switch' and pressure selling, but unfortunately does not have the power to insist that TalkTalk undertake a root and branch review of the degree to which misselling of services is endemic within the organisation and to determine whether any customers were hoodwinked by TalkTalk's toxic sales practices in order to make them good.
This finding confirms my suspicions that the call I received was not the result of a single 'rogue operator' but a systemic culture within TalkTalk of misleading customers in order to coerce them to upgrade their services.