Scottish Power has been ordered to pay some of its customers a total of £8.5m by Ofgem following an investigation into the firms telephone and doorstep selling.
The energy regulator ordered the 'Big Six' energy supplier to pay the fine as a result of its failure to train and monitor its staff properly, resulting in a number of customers being misled by certain representatives of the firm between 2009-2011, up until it stopped the practice of doorstep selling.
Ofgem senior partner, Sarah Harrison, who is responsible for enforcement, said: "Today's announcement is a clear signal to energy suppliers of the consequences of breaching licence obligations."
The firm will pay the vast majority of the money, £7.5m, to its 140,000 customers currently on the Warm Home Discount Scheme, a government led scheme designed to aid those energy consumers most at risk of falling into fuel poverty.
The firm estimates the pay outs will average out to be around £50 per customer.
A further £1m will be put into a special compensation pot for customers who believe they have been mis-sold by the firm.
Ofgem said the size of the fine reflected co-operation on the part of Scottish Power, and it found no deliberate policy in place by the energy firm to 'deliberately mis-sell to customers'.
Scottish Power CEO of retail & generation, Neil Clitheroe, said: "We accept Ofgem's findings and we apologise unreservedly to those customers affected.
"This arose as a result of new regulations which were introduced in 2009. I am sorry to say that we didn't implement these properly at that time.
"However, I am pleased that Ofgem has made it clear that they found no evidence of a strategy by Scottish Power to deliberately mis-sell to customers.
"Since 2011 we have taken determined steps to resolve the problem: doorstep selling was stopped; and all telephone sales staff are properly trained and monitored."
As part of the Green Deal, a government scheme designed to cut down carbon emissions in the home while improving energy efficiency, Scottish Power offers customers loans on energy-saving measures including the fitting of new energy-efficient boilers or wall insulation.
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