The team at Money Saving Expert have found that British Gas is the 'worst company to be moved to' in a new survey.
Following the energy price crisis, over 40 energy firms collapsed as wholesale prices hit record highs in September 2021.
Due to their being lack of competition and staggering gas prices, companies have not been able to provide energy deals, like they used to.
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So when a company went bust, their customers were automatically moved to another firm by energy regulator Ofgem.
However in a survey by consumer champion website Money Saving Expert, British Gas is one of the 'worst' firms to have been moved.
MoneySavingExpert.com asked 12,000 respondents and found that British Gas customers were the least happy with their provider.
MSE also added that EDF and Shell Energy also performed poorly.
The research found that nine in 10 customers who had moved from PFP Energy or People's Energy to British Gas, had been waiting more than four months at the time of the survey.
The customer service was also marked down for a number of energy firms.
According to MSE, at least half of those contacting British Gas, EDF and Shell Energy by phone, email or live chat (for any reason) said they had not found it easy to do so.
MSE founder Martin Lewis has said that energy companies need to do better.
He said: "Over the past six months, the challenge to the energy industry, due to huge spikes in wholesale costs, is unprecedented. Dozens of providers have collapsed, far beyond anything the Ofgem 'safety net' was designed to cope with, leaving the remaining firms struggling to pick up the pieces."
He added: "Of course, some of the problems may well be down to the data infrastructure the fallen firm left behind. Yet the consistency in poor feedback for British Gas, Shell Energy and EDF, regardless of which firm's customers they were taking over, suggests it isn't just that.
"These providers must up their game, and Ofgem must do more to ensure those caught by its safety net don't end up trapped in it."
You can see more of the survey from Money Saving Expert here.
A British Gas spokesperson told Edinburgh Live: "Since August 2021 around 4 million customers have been left without an energy company due to the multiple supplier failures in the energy market.
"As a responsible business, in the last six months we’ve stepped in to take over the energy supply of over 700,000 customers from eight different failed suppliers, this is the largest proportion across the industry in terms of number of customers and in terms of number of failed suppliers.
"Unfortunately, each of these suppliers has its own process in terms of how they share data, including around credit balances and we are reliant on their processes.
"In some instances this has taken longer than we would have liked and we appreciate this is unsettling for customers. The majority of credit balances have now either been applied or will be shortly, and we have been in touch with individual customers where there has been a delay."
Were you automatically changed to a different energy provider? How was your experience? Let us know in the comments.