The Communications Ombudsman has already taken on 17,695 cases to June this year, up from 11,466 cases over the same period last year, it said.
Service quality complaints are up from 2,795 in the first half of last year to 3,605 so far this year, while customer service grievances have ballooned from 1,716 last year to 3,934 since January this year.
Complaints about contract issues are up from 1,268 to 1,895, the service’s data shows.
Andy Eadle, business unit director at the Communications Ombudsman, said: “We’ve seen an increase in complaints across all dispute categories, but primarily in service quality, or speed and reliability of service, and billing – continuing into the first half of 2024.
Meanwhile, consumer complaints to the Energy Ombudsman are down by more than a fifth on last year but billing, smart meters and customer service continue to cause households the most problems.
The service handled 22% fewer complaints in the first half of 2024 compared with the same period last year, down from 68,186 cases to 53,210.
Complaints about billing, such as disputed usage and balances and estimated billings and readings, fell from 37,344 between January and June last year but remained the most common grievance, with 32,588 cases so far this year.
The service has handled 6,038 cases of problems with customer service so far this year, down from 8,108 over the same period last year.
Smart meter problems have led to 5,059 cases this year, down from 8,428 between January and June last year.
Ed Dodman, business unit director at the Energy Ombudsman, said: “Last year was an unprecedented time for many with the cost-of-living crisis impacting the country.
“Billing remained the most common reason for disputes into 2024, as consumers kept a closer eye on how their energy use is measured and how they pay for it.
“While case numbers have decreased to pre-2023 levels, we remain committed to increasing awareness of our service so that it remains accessible for all who need it.”
Mr Dodman added: “Last year followed an unprecedented period for the energy sector, which saw prices hit at an all-time high, and a number of suppliers leave the market.
“In this context, it’s understandable why we saw people turn to the Energy Ombudsman to make sure they were being treated fairly.
“As the market has stabilised somewhat, we have seen the number of complaints reduce this year, but they remain higher than they were before the crisis.
“Ultimately, it’s important people understand their rights, including how and when they can use our service.”
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