ScottishPower has been ordered to clean up its act by Ofgem – or face a sales ban.
It follows an investigation which showed the Big Six supplier did not answer customer queries promptly, had an excessive billing backlog and failed to resolve complaints made to the industry ombudsman, the energy regulator said.
ScottishPower has now signed up to targets to improve customer service within three months and resolve all the issues.
Currently, the supplier is late in issuing more than 75,000 bills and this must drop to 30,000 by the end of December.
Failure to meet any of the targets “will result in a suspension of sales activities”, Ofgem said.
The regulator has also launched a separate investigation into the supplier’s treatment of customers.
Sarah Harrison, Senior Partner in charge of enforcement at Ofgem added: “In a properly functioning market we would expect companies to compete keenly on service. The need for our intervention here is yet more evidence the energy market is not working for consumers.
“This is a clear signal to suppliers to up their game and give consumers the service they are entitled to.”
ScottishPower’s Chief Executive Neil Clitheroe said: “I would like to apologise unreservedly to any customer who has not received the level of service that they deserve from Scottish Power in recent months and provide my personal assurance that we will do what we can to correct every problem, pay appropriate compensation and ensure that no customer is disadvantaged.”