The performance of some smaller and newer energy suppliers has been called into question as Citizens Advice customer service star ratings reveals TOTO Energy and Solarplicity are bottom of the league.

Out of a maximum of five stars, TOTO Energy received a score of 1.45, covering the period between April and June 2018. This is down from the 1.6 stars rated by customers in the previous quarter.

The charity said it had dealt with problems from TOTO Energy customers relating to being unable to contact the company and billing issues.

In one case dealt with by Citizens Advice, a customer said their direct debit was hiked by £100, while in another case, they were unable to get through to TOTO Energy for two weeks to resolve their issue.

On average, TOTO Energy customers spent an average 23 minutes on hold, and one in 10 waited over a year to receive an accurate bill from the supplier.

The charity said Solarplicity, which appears in the table for the first time, has ranked second from bottom as it received a lowly score of 1.8.

But at the opposite end of the scale comes So Energy which received a score of 4.7. See this link to find out where your energy company ranks.

Citizens Advice is calling for greater regulation of smaller and newer energy companies, adding that poor customer service is “damaging people’s experience and trust in the market”.

Gillian Guy, chief executive of Citizens Advice, said: “Too many customers are being let down by firms which aren’t ready or capable of providing a decent level of service.

“These aren’t small problems. Billing errors, blocking people from switching, and poor communication can cost customers money and make people’s lives a misery.

“It’s vital Ofgem now tackles the problem of newer and smaller firms letting people down and tightens up the rules around who can become an energy supplier.”

What does TOTO Energy say?

Jim Butler, CEO of TOTO Energy, said: “We’ve made significant improvements in our customer service in the three months since this Citizens Advice star rating was taken. We promised to put measures in place to be better right across the business, and we’re confident they’re working.

“Call wait times have fallen by over 70% to five minutes and customer complaints have reduced by over 45% between the second and third quarter of 2018.

“I apologised to our customers for falling short of the standard they expect during this period and we will continue to work with our regulator, Ofgem and consumer organisations including Citizens Advice to ensure that our customers can be confident we’re heading in the right direction.”

Related: See YourMoney.com’s Record number switch to small energy suppliers: how safe are they? for more information.