Auckland Council has suspended a home improvement scheme after uncovering billing errors for thousands of ratepayers.
Loan interest payments for its Retrofit Your Home programmes were wrongly calculated.
The council's treasurer, John Bishop, said it expects to refund more than 20,000 people at a total cost of almost $10 million.
The Commerce Commission today warned the council over the bungled home heating and insulation scheme, which has been suspended.
More to come.