BT and NTL are the home phone companies that UK consumers are least satisfied with, a Uswitch survey has found.
Talk Talk customers are the most happy with their service, say Uswitch
NTL came last and BT second to last in the poll of almost 9,000 people carried out for the price comparison website.
TalkTalk, the phone and internet service offered by Carphone Warehouse, topped the customer satisfaction poll.
But trust in suppliers was low across the board, with less than half of those quizzed believing their provider makes sure they are on the best deal.
Uswitch said that since only 48% of consumers believe they are on the best deal, that means almost 12 million customers are not sure whether they are on the right package for their needs.
Talk Talk - 89%
Tiscali - 88%
Sky Talk - 87%
Telewest - 83%
Homecall - 82%
BT - 75%
NTL - 72%
In total, 56% of both BT and NTL customers did not believe they were on the right package.
But the figures were not much better for the pair's rivals - 43% of Tiscali and 46% of Telewest customers believed they were on the wrong deal.
Even TalkTalk, which ranked highest in the poll, achieved only a 65% satisfaction rating in the category.
Following the survey, NTL said it was aware of areas that "needed improvement".
A spokeswoman said that following its recent takeover of Telewest, NTL had uncovered areas where Telewest had fared particularly well and these measures would be taken on across the group.
However, BT dismissed the results, saying that Uswitch polls were "far from impartial".
"Uswitch recommendations are becoming as predictable as Groundhog Day," John Petter, chief operating officer, BT Retail said.
"They make a very lucrative living from undisclosed competitor commissions and have been criticised recently for the reliability of some of their data.
"While BT is far from complacent, we suggest a more accurate indication of our customer performance is that, in an extremely competitive market, BT is still by some distance the leading telephone and DSL broadband supplier."
But Uswitch denied BT's claims, adding that the poll was an independent one - carried out by YouGov - which questioned the actual customers of the firms named in the survey.
The group also stressed that it was the "only home phone calculator to be a member of the Ofcom PASS scheme" - which ensures websites conform to strict rules on providing independent and accurate information.