TalkTalk believes many broadband providers are not doing enough to reward customers that stick with them.
Earlier this week, Citizens Advice warned that loyal broadband customers are paying a swingeing premium for sticking with their provider after introductory rates end.
Figures showed that the prices of the cheapest broadband deals go up by £113 a year - or 43 per cent - on average after their initial low-cost teaser rate comes to an end.
Citizens Advice therefore urged broadband providers to help customers avoid significant price hikes by being clearer about what they will charge after the introductory deal ends.
This, it said, means they should include up-front information in marketing materials and when people sign up for a contract, as well as alert people when the fixed price comes to an end.
Responding to the report, a spokesperson for TalkTalk told the Sun: "We agree that all too often loyal customers are treated poorly by their broadband provider.
"This is why last year we launched our new Fixed Low Price Plans which rewards loyal customers by guaranteeing there will be no price increases for the length of their contract."
TalkTalk has introduced fixed price plans for 12, 18 and 24-month contracts, which offer a guarantee that prices will not go up during this period.
Citizens Advice had flagged up the company as one major provider that had imposed so-called loyalty penalties, with a 24-month contract going up in price by £66 (or 28 per cent) when the introductory deal ended.
Interestingly, Virgin Media was found to be the only one of the five biggest broadband providers that did not impose a loyalty penalty when the initial term of a contract expired.
In its response to the Citizens Advice report, it said: "We’re always mindful about providing our customers the best deals across Virgin Media’s range of packages."