I have never used TalkTalk and I never will, simply because of the stories I read about them on here and because of the leak they had a couple of years ago that they tried to cover up.
However... there are others just as bad. I've just got out of my Virgin media contract a little early because of 'utilisation' issues... Which basically means their network isn't capable of supporting the number of customers they have. This was proven over the course of several months by taking daily screenshots of various speed tests, that showed an average of 20Mbps on a 100Mbps line. Speeds would drop as low as 68Kbps but never higher than 30Mbps.
So I switched to Vodafone in March... and have already terminated my service because they couldn't even transfer my number. Confirmed with Virgin that they've never even requested it.
Virgins customer dept are pretty useless dealing with things, and you have to escalate a complaint and threaten to take it to the regulator before they respond.
Vodafone simply ignore ALL complaints, and you have to email the ceo nick.jeffery@ before they pay attention.
I am currently in limbo... there's a phone line with a temp number blocking the line... I'm still paying Virgin for a phone line and I can't get a new broadband provider installed until Vodaphone terminate the line... Because any new provider will try to take over the temp number and not my actual number.
The moral of this story... all 3 of these providers (TalkTalk, Virgin & Vodafone) are a bunch of lying, deceptive, unfit for purpose feckwits... and No one should ever use them at all.