More than 4000 customers of Commonwealth Bank have so far asked that advice they have received be reviewed in the wake of the bank’s financial planning scandal.

That is a small proportion of the bank’s 400,000 financial planning customers, but it is expecting more complainants to line up as it continues to increase awareness of the “open advice review” program.

“The program has been advertised extensively across a number of channels including print, online and radio,” the bank’s statement said.

“The open advice review program has contacted almost all customers who have registered and will continue to proactively do so via the program’s dedicated customer contact centre.”

The latest update comes almost three months after CBA apologised for dodgy advice provided by some planners that resulted in unnecessarily customers losing their savings.

The CBA’s financial planning scandal has already cost the bank $52 million in compensation to more than 1,100 customers. The bank has not put a figure on how much it has set aside for new complainants.

In late June, a Senate report found Commonwealth Bank customers lost hundreds of millions of dollars because financial planners put their clients’ money into high-risk investments without their permission.

The damning Senate report called for a royal commission into the affair.

A week later, the bank’s CEO Ian Narev said CBA’s previous performance in financial planning was “unacceptable” and launched a program to compensate people who had lost money.

The bank has since been offering a free assessment or “open advice review” to customers who received advice from Commonwealth Financial Planning between September 2003 and July 2012.

Once the customers’ situations are assessed, the bank may make a compensation offer.

The program, announced on July 3, 2014, is open for 12 months.

Global financial services firm Promontory Financial Group, led locally by Jeff Carmichael,  is overseeing the bank’s internal review process and his reports will be made public.

If CBA customers do not agree with the outcome of the initial review, they can seek a second opinion from an independent panel led by former high court justice Ian Callinan. This will be the binding decision.