Abbey is reviewing every complaint it has rejected since January 2000
BBC Radio 4's Money Box was broadcast on Saturday, 28 May, 2005, at 1202 BST.
The programme was repeated on Sunday, 29 May at 2102 BST.
Mortgage lender Abbey is reviewing about 50,000 endowment complaints after it was fined £800,000 for mishandling 5,000.
The Financial Services Authority said Abbey mishandled the complaints during October 2001 and September 2003.
It said 3,500 were rejected when they should have been upheld.
The Financial Ombudsman Service has prepared an FAQ page for anyone concerned they may be affected.
Based on industry averages, the regulator said losses of up to £19 million may have been caused to customers.
Consumer association Which? said it was shocking to find that so many people had their complaints treated so badly.
Abbey has accepted its complaints procedures were inadequate and is now reviewing every endowment complaint it has rejected since January 2000.
Paul Lewis asked Louise Hanson of Which? what this means for consumers.
Warning on equity release
Many advisors are not carrying out proper checks before recommending equity release to consumers, the Financial Services Authority has found.
Britons borrowed £1.2bn through equity release in 2004
In a mystery shop of 42 product providers, independent financial advisors, and mortgage brokers, the regulator discovered 70% were not gathering enough information to assess their clients' suitability.
And 60% of advisors were not properly explaining the downsides of equity release.
The FSA has warned advisors to address its concerns, and added that it had not ruled out enforcement action.
Paul Lewis spoke to Clive Briault of the Financial Services Authority about the findings.
Community Investment Scheme
The Community Investment Scheme enables individuals to invest lump sums and get valuable tax relief, sometimes with interest on top, which provides one of the best returns around.
But it is not always without risk and needs careful consideration, as Samantha Washington reported.
Bristol & West sells branches for £150m
Almost a million Bristol & West savers are to be moved to Britannia Building Society following its purchase of all 97 branches for £150 million.
The branches are mainly in the South West of England
Bristol & West customers are not being asked their opinion and will not get a windfall payment.
But Britannia says it will guarantee no-one will get a worse rate on their savings than they do now.
Paul Lewis spoke to Neville Richardson, Chief Executive of the Britannia about the shock announcement.
Fines aim to cut phone 'slamming'
Fixed-line phone operators who switch consumers to their service without consent, a practice called "slamming", face hefty fines from Thursday.
Presenter: Paul Lewis
Producer: Chris A'Court
Reporter: Samantha Washington