Former customers of Extra Energy who had £100s' worth of credit left on their accounts when they switched suppliers have been left waiting months for refunds. The energy company has blamed the delays on an IT issue and says final statements are now being sent to affected customers. has been contacted by frustrated former Extra Energy customers who have experienced long delays in claiming back credit left on their accounts when they switched to a different energy supplier.

Extra Energy has acknowledged the issue and says that problems with its IT system meant it could not generate some customers' bills. It says this has now been resolved and that statements are being sent to those affected. The firm added that bills can be processed manually if required – yet this approach does not appear to have been applied in certain cases.

Julie Salloway, who switched energy supplier on 19 September, says: "I was £212 in credit with Extra Energy. I have contacted them to [ask them to] refund this money and have been told that the computer is unable to calculate the final payments and therefore [they] cannot return my money.

"They do not know when the problem will be fixed and they promised to call me back on 7 November but have not done so. I'm concerned I will not get my money back."

Joan Thirlwell, who's due a £118 refund after switching supplier, adds: "I switched supplier on 12 September and have heard nothing from Extra Energy since, and my online statement shows June 2016.

"I rang [on 8 November] and was told they were busy and that someone would come back to me. I then had the call back to say that there were technical problems in issuing the final statements and the directors were looking into it. I asked about the refund and was told this could not be refunded until the final statement issue was resolved."

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What does Extra Energy say?

A spokesperson says: "Extra Energy are aware of a recent issue with generating final bills for customers over a short period of time. We take every incidence of a delay in calculating credit on a final bill incredibly seriously, and where there is a delay accounts can also be manually billed if required.

"This issue has now been rectified and all final invoices are in the process of being released to affected customers. Extra Energy apologised for any inconvenience that this has caused.

"Issues with our technology are extremely rare, but these issues do occasionally affect all businesses. We are working tirelessly to ensure that this does not happen again."

Extra Energy wouldn't tell us how many of its former customers have been affected by the delay in refunding credit left on accounts. Let us know if you've been affected by emailing

What should I do if I've got a complaint to make?

If you've a gripe with Extra Energy, you should complain to the company. If you're unhappy with the response received or don't get one at all within eight weeks, you can take your complaint to the ombudsman.

Mounting number of complaints against Extra Energy

Complaints made by Extra Energy customers have been widespread over the past year – between January and March 2016 the company was ranked bottom of Citizens Advice's energy supplier table for handling customer complaints.

Across this period, Extra Energy had 1,682 complaints per 100,000 energy customers – the highest complaints ratio recorded in the table's five-year history.

Energy regulator Ofgem subsequently launched an investigation over concerns that industry rules had been broken over billing, customer service and complaints handling. These rules are designed to ensure that suppliers treat customers fairly.

When the investigation was launched, Extra Energy claimed that many of its customers' original complaints about billing problems would be resolved by a new billing system, which ensured customers received bills quarterly.

Six months later – in September – the company again finished bottom of Citizens Advice's supplier table, with 1,791 complaints per 100,000 customers between April and June 2016.

We're seeking clarification on when the Ofgem investigation is likely to conclude. If the regulator decides Extra Energy did breach the rules, it has the power to impose a fine of up to 10% of the company's turnover.