Npower is Britain’s most complained about energy supplier, according to new figures published today.
The German-owned company, which imposed the highest price rise last winter, received 10 times as many complaints as its best performing rival.
Data from the Citizens Advice Bureau showed that between October and December last year, Npower received 306 complaints for every 100,000 customers.
This represents a 300% rise since January 2012.
More bad news for Npower
This news is the latest in a series of blows for the firm, which was rated worst energy company in the 2013 Which? Switch satisfaction survey.
In December last year, Npower was fined for breaking sales rules and agreed to pay a whopping £3.5m towards helping vulnerable customers.
This followed a £2m fine in January 2012 for poor handling of customer complaints. British Gas was also fined following the same investigation.
Complaints about Big Six energy companies
Scottish and Southern Energy (SSE) was the best performing of the energy companies, attracting 31.5 complaints per 100,000 customers.
British Gas came second receiving 53.7 complaints.
Energy firm EDF was the third, receiving 62 complaints for every 100,000 customers, while E.ON came fourth with 55.8.
In fifth place was Scottish Power, which attracted 100.5 complaints per 100,000 customers.
Among the top gripes were bills arriving late, payments being stopped and new accounts not being set up.