Bank of Scotland was the most complained about financial services provider in the first six months of this year, according to the Financial Ombudsman Service (FOS).
The FOS received 61,664 complaints about the bank during the period - up 57% from the last six months of 2012 - and 80% of those complaints were upheld.
Lloyds TSB took second place with 59,753 complaints - up 31% on the previous six-month period - 86% of which were upheld.
Barclays was the third most complained about bank with the FOS receiving 43,612 complaints and upholding 64% of them. However compared to the last six months of 2012, the number of complaints fell by -2%.
In relation to PPI alone, the same three providers also took the same places in the top three. Bank of Scotland was also the worst offender with 57,680 complaints, followed by Lloyds with 55,972 and Barclays with 37,394 complaints.
Natalie Ceeney, chief executive and chief ombudsman at the FOS, said: "During the first six months of this year we sorted out a record number of complaints for people - making real progress in tackling the customer-service fallout from the mis-selling of PPI, widely accepted as the largest financial mis-selling scandal.
"Disappointingly we are still seeing cases where businesses are not following our long-standing approach to PPI, resulting in long waits and unnecessary delays for consumers.
"But, more positively, we are seeing encouraging signs from some major businesses that are starting to recognise the value of getting things right for their customers - with an increased focus on sorting out problems and concerns as quickly as possible."
Top 10 most complained about banks during 1 January to 30 June 2013
Bank of Scotland, 61,664
Lloyds TSB Bank, 59,753
Barclays Bank, 43,612
MBNA Europe Bank, 15,187
HSBC Bank, 14,869
Capital One (Europe), 12,048
Royal Bank of Scotland, 11,268
Nationwide Building Society, 8,539