Rail customers' satisfaction ratings with value for money have gone up just seven percentage points in the last decade - despite fares having risen by 54% over the same period, according to Which?
Passenger satisfaction with value for money across all the train operators has gone from 41% to 48% in the Which? National Rail Passenger Survey.
The consumer organisation said the figures showed "little meaningful improvement".
Commuters are only 34% satisfied with value for money, a figure that has also increased by only seven percentage points in 10 years.
But the increase in ticket prices is more than double the rate of Consumer Price Index inflation.
Some train operators did see improvement - Abellio Greater Anglia saw satisfaction levels go from 28% to 42% of customers - but Northern Rail saw ratings go down - from 61% to 58%.
In December 2015 Which? lodged a super-complaint to the Office of Rail and Road (ORR) calling for urgent improvements to make it easier for passengers to claim refunds for rail delays and cancellations.
Following the regulator's response, Which? is now calling on the Government to ensure that the ORR has new powers and duties to enable it to be a strong, independent regulator that stands up for passengers.
Where breaches of consumer law and licence conditions have been found as part of the investigation for our super-complaint, the ORR must take enforcement action "without delay", Which? said.
Which? executive director Richard Lloyd, said: "Despite repeated claims that the railways are improving, passengers say that rail travel offers little more value for money than a decade ago.
"What's more, people have found even less of an improvement in the way train companies handle delays.
"This is an unacceptably slow pace of change, so the Government must quickly now give the rail regulator the powers and duties it needs to be an independent consumer watchdog that can hold train operators to account."