British Gas has landed itself in hot water because it mistakenly increased the periodical bills of thousands of its direct debit customers without given them prior warnings, financial news website This is Money has reported.

The increases to the automatic payment scheme come in association with the energy provider’s fresh round of tariff rises in response to increasing procurement and supply costs. However the Centrica group company failed in its duty to inform its direct debit customers of the changes before making the adjustments to what they pay.

British Gas’ price hike is its second of the year. As it announced in July the company has now increased its gas tariffs by 12.4% and electricity tariffs by 9.4%.

According to uSwitch, British Gas’ prices are now on average 18% higher than its big rivals for gas and 17% higher for energy, making it stand out as Britain’s most expensive major energy provider.

According to the media report, British Gas is in the process of writing to its affected customers to apologize for the error, which it said was due to a production problem.