TalkTalk has been fined £3 million by Ofcom after mistakenly billing thousands of customers even after they had closed their accounts.
Over 62,000 customers were wrongly billed by TalkTalk and its subsidiary Tiscali between January and November 2010, leaving the company with the lowest consumer satisfaction of all the UK's broadband and landline providers.
Ofcom ordered TalkTalk and Tiscali to sort out their billing issues by December 2010 but, despite taking some steps to stem the problems, the companies continued to incorrectly charge almost 3,000 customers up until March 2011.
Harsh but fair
The £3 million penalty, Ofcom says, is to "reflect the seriousness of their breach of the rules and to act as a deterrent to them and other telecoms companies who must comply with the rules" and could have been higher had TalkTalk not taken steps to rectify the issues.
The company has also paid out over £2.5 million in refunds and compensation to more than 65,000 affected customers.
TalkTalk's chief executive Dido Harding said in a statement to TechRadar: "Last year I recognised that we needed to invest in our systems, processes and customer services and we are making significant progress.
"We are of course disappointed at the scale of the fine and feel it is a disproportionate penalty; however we are striving to continually improve and invest in customer experience and are pleased at the clear progress we are starting to make."