AMP says it is committed to ensuring customers are compensated as quickly as possible over the charging of fees for no service.
AMP is blaming "a few bad apples" for its "almost unimaginable" fees-for-no-service problems that are now expected to cost almost $800 million to fix.
Australia's largest wealth manager is accelerating its remediation program for customers charged fees for no service or given inappropriate advice, wanting the compensation paid out within three years.
Acting CEO Mike Wilkins argued a small number of individuals in AMP's advice business decided not to follow policy and inappropriately charged fees to customers where no service was provided.
Banking royal commissioner Kenneth Hayne QC asked if he meant there were a few bad apples, and Mr Wilkins agreed.
Mr Wilkins said policies were in place for when fees were to be turned off.
"Those policies were not followed and there have been subsequent consequences for those people who didn't follow that policy," he said on Wednesday.
An early estimate put the cost of the remediation program at more than $1 billion, but AMP now expects it will be completed sooner and cost $778 million.
It expects to pay $440 million to clients, mostly for fees for no service, but is still reviewing the files of more than 217,000 customers.
Even if AMP met its completion target, some customers charged fees when no advice service was provided in 2008 would have waited a dozen years for a refund - still faster than the 17 year extreme case scenario under its initial time frame.
Senior counsel assisting the commission Michael Hodge QC questioned Mr Wilkins' assertion that clients could have confidence in AMP because it had the size and capital backing to make good the problem.
Mr Hodge said it seemed like an extraordinary proposition that it was possible to preside over an almost unimaginable level of taking money from clients without providing a service, but at least customers could be confident it would be able to repay them 12 or 17 years later.
Mr Wilkins said clients should have confidence in a large financial institution.
"It might take us awhile but ultimately we will do the right thing to remediate them," he said.
The inquiry on Tuesday heard AMP may have another potential fees-for-no-service problem as it investigated the provision of general advice to corporate superannuation plans.
AMP on Wednesday told the stock market the matter was under review but the amount involved was unlikely to be material.
AMP shares lost 3.3 per cent after the update to the royal commission about the scale of its fees-for-no-service issues.