Just over half of broadband and mobile customers who moaned to their provider were satisfied with how their complaints were handled, according to a report by UK regulator Ofcom.
Sky customers had the highest levels of satisfaction with how their complaint was dealt with in the last six months of 2016 (61 per cent), while TalkTalk customers had the lowest (51 per cent), according to the survey of 6,733 people.
Meanwhile, Tesco Mobile customers were most satisfied (74 per cent), while Vodafone customers had the lower levels of satisfaction (46 per cent).
The report, titled Comparing Service Quality, discovered that Virgin Media and TalkTalk had the highest proportion of broadband customers with a reason to complain in 2016 (both 16 per cent).
Ofcom recently published proposals to require providers to pay automatic compensation to landline and broadband customers who suffer slow repairs, late installations or missed engineer appointments. Ofcom estimates that the plans would mean up to 2.6 million additional customers could receive up to £185m in new compensation payments each year.
The regulator has today launched a checker to allow phone and broadband customers to compare how providers rate for answering customer calls, handling complaints, and reliability of their services.
Sharon White, Ofcom chief exec, said: "We're determined to help bring about a service revolution in the telecoms sector, where consistency and excellence become the norm, and customers always come first.
"Today we want to shine a light on how different providers perform, and are challenging the industry to up its game on customer service. We'll be monitoring closely to ensure industry service standards are raised."
Overall, 92 per cent of mobile, 89 per cent of landline and 87 per cent of broadband customers were satisfied with their service. The data draws on a combination of consumer research and complaints figures, as well as statistics obtained directly from providers that have never been published before.
Ofcom has also compared the performance of 19 popular broadband packages from seven internet providers. The average UK broadband download speed reached 36.2Mbps in November 2016 – an increase of 7.3Mbps (25 per cent) since November 2015.
The average UK upload speed was 4.3Mbps in November 2016, an increase of 0.6Mbps (16 per cent), compared to the previous year.
Of the packages compared, Virgin Media's "up to 200 Mbps" cable package achieved the fastest download speeds (averaging 173.1Mbps over a 24-hour period and 149.5Mbps during the 8-10pm peak period).
However, it found the speeds offered by providers are not consistent throughout the day, and can fall significantly during busy periods due to people going online at the same time.
Providers take an average of 13 calendar days to get a new broadband service up and running; 16 days to set up a landline service, and 16 days to install a landline and broadband service together. ®