I have beeen with TalkTalk for about years. Initially I paid £10 per month for broadband but it becomes free when the local telephone exchange ecomes unbundled (LLU).
I discovered that our exchange had been unbundled for some time so asked at the local Carphone Warehouse when my line would be switched. I was given a date but nothing happened, so complained and got another date. Still no joy. I was then told that the problem as getting a BT engineer to make the change. I then e-mailed the office of Charles Dunstone and was contacted by someone by phone who told me when the changeover would occur. I then received a phone call every day advising of progress until the changeover had occurred and then to check that the new modem was correctly installed and working. I was also financially compensated for the delay in switching my telephone line.
So I would say that, as with any large organisation, there will be times when things go a bit awry but, needless to say, I am well satisfied with the service from TalkTalk and the measures that they took.