Customers of Britain's biggest energy supplier, British Gas, might not be very happy to hear the firm's interim profits have soared by 23% to £345m. Especially when it seems their energy bills keep going up.

Centrica overall made adjusted profits for the first 6 months of this year of £1.45 billion, and the boost in fortunes for the Residential Energy Division of British Gas was partly attributable to the cold weather between April and June.

British Gas customers really seem to be on a rollercoaster with the firm. According to Consumer Focus, last August it put electricity prices up 16% and gas prices up by 18%. Then in January, it cut the Standard Electricity tariff by 5% and then – in an about face, two months ago – it warned account holders there'd be an increase in this year's winter bills to compensate for rising cost of wholesale gas.

So it's no surprise then that fair deal groups like Consumer Focus say they're 'shocked' about the 'disconnection between profits and prices' which they say will risk 'deepening consumer mistrust'.