'Big six' energy firm Npower has today (Tuesday) confirmed its plans to cut 2,400 jobs in the UK following a dismal 2015.
The number of cuts is slightly lower than expected, but the scale of Npower's struggles last year is worse.
The energy supplier, owned by Germany's RWE, posted a loss of €137 million (£106m) for 2015, compared with a €227m profit in 2014. It had been thought that Npower lost around 200,000 customers last year, but that figure was in fact considerably higher at 351,000.
Npower was fined a record £26m by energy regulator Ofwat last year over inaccuracies in its billing, and failure to handle complaints over the problems sufficiently. And RWE warned that the billing issues are likely to continue throughout this year.
As a group, RWE posted a loss of €637m, compared with a profit of €2.2 billion in 2014.
Npower chief executive Paul Coffey, said: "They [the results] show a business that tried to do too much, too soon while not focusing enough on the fundamentals in a constantly changing market. This led to over complicated processes and procedures resulting in unhappy customers, too many complaints and extra costs to put things right."
RWE blamed government schemes and efforts to make homes more energy efficient for some of its problems over the past year.
It said: "Under Energy Company Obligation major UK energy firms such as Npower are obliged to finance measures to increase the energy efficiency of households and are therefore at a cost disadvantage compared to smaller providers, which do not have such obligations."