It will be years before the Payment Protection Insurance (PPI) mis-selling scandal is over, according to the chief financial ombudsman, Caroline Wayman.
Complaints about the behaviour of banks and credit card companies who mis-sold PPI are still running at 4,000 a week, she said.
However at the peak of the scandal in 2012 there were 12,000 complaints a week.
Banks alone are now thought to have paid out around £22bn in compensation.
In total, the Financial Ombudsman has dealt with 1.25m complaints - and that does not include complaints made directly to banks and credit card companies.
"Although numbers are slowly declining, it will be years before we can truly say this mis-selling scandal is over," said Ms Wayman.
However she said that the total number of complaints sent to the Financial Ombudsman was "starting to stabilise".
Nevertheless the Financial Ombudsman service is to recruit a further 200 staff as adjudicators and ombudsmen.
It has already doubled in size to 4,000 staff, to handle the surge of PPI complaints.
The scandal stretches back to the 1990s.
Over that period millions of customers were mis-sold insurance policies to protect themselves against falling ill or losing their jobs.
The policies would pay off any outstanding loans, such as credit card bills or mortgages.
However many people did not need the policies in the first place, and many were unaware they were paying for them.