Complaints made to the Financial Services Ombudsman rose by more than a quarter last year, figures reveal.
The watchdog received 7,600 calls from disgruntled consumers in 2009 - up 28% on the previous year.
Insurance firms were the subject of almost 4,670 of the complaints, with 2,951 grievances relating to banks, building societies and other credit institutions.
Ombudsman William Prasifka predicted even more complaints would be lodged in coming years. "The years ahead will continue to be challenging," he said.
"The continuing financial and economic crisis will place increased demands on the office. The public will quite properly demand a high level of service from us."
The recession meant some institutions were unable to pay out awards made by the ombudsman, Mr Prasifka added.
Last year the Financial Services Ombudsman received more than 17,000 telephone calls while around 200,000 visits were made to its website. Of 6,200 grievances resolved last year, three out of five were settled in the complainant's favour.
Among the directions made were for 345,000 euro to be paid back to a couple in their 70s who had been approached by their bank to have their life savings invested in a managed fund. The ombudsman found the bank had rushed through the investments with unacceptable haste and failed in its duty of care to the pair.
In another case a retired farmer was awarded 250,000 euro - the maximum compensation possible - for the "cavalier approach" and belittling remarks made by a bank with regard to investments he and his wife had made.
Financial services providers with complaints made against them are not named and shamed by the ombudsman. The watchdog has contacted Minister for Finance Brian Lenihan, however, to consider whether the rules should be changed to allow the institutions` identities to be revealed.