Energy company SSE has lost more than 500,000 customers in the past 12 months as customers continue to turn their back on the Big Six.
The UK's second biggest energy company now has 8.5 million account holders – its smallest customer base since 2008 – and blamed "increasingly challenging and highly competitive market conditions" for the fall.
However, SSE reported a 39% increase in profits to £456.8 million for the year to 31 March, thanks in part to a price hike in its electricity and gas tariffs in November 2013.
In a bid to play down its improved performance, SSE's group managing director for retail Will Morris, said: "Following a difficult 2013/14, our profit margin across the whole of Energy Supply returned to a more typical level of 4.6%. For household customers, we made around £68 of profit on a typical dual fuel bill of £1,158; from that profit we pay tax and interest."
SSE, which operates as Scottish Hydro, Swalec, Southern Electric and Atlantic, was also keen to point out that it now has a price freeze on tariffs until July 2016.
Morris added: "In January we announced our second price cut in 13 months, as well as extending our already unprecedented price cap commitment to July 2016. This will mean our customers will not have seen a price increase for more than two and a half years. Prices will, in fact, have fallen twice in that time."
Its latest price cut was a 4.1% reduction for gas bills as of 30 April 2015 that saves customers a measly £28 a year on average.
Ann Robinson, director of consumer policy at comparison site uSwitch.com, said: "With the threat of a Labour price freeze now off the table, the Big Six have officially run out of excuses for not making proper, double-digit reductions to customers' bills, following significant reductions in the cost of wholesale energy.
"The modest cuts by the Big Six so far this year have simply not gone far enough, and the fact remains that SSE was the last of the big six suppliers to implement a standard gas tariff reduction this year."
She added: "Given falling wholesale energy prices, suppliers must do the right thing and urgently make further cuts to the price of gas and electricity for hard-pressed consumers."