"When PPI is taken out of the mix, the numbers of complaints firms are receiving has remained stable."
Blemain received 43.1 complaints per 1,000 balances outstanding, followed by Kensington with 41.12 and Charter Court with 33.9.
In total, the FCA received 3.76 million complaints about financial services firms in the second half of 2017, a 13% increase on the previous year, driven mainly by complaints about PPI.
Complaints about PPI rose by 40% to 1.55 million, the highest level of complaints about PPI for more than four years.
In January 2018 firms paid out £415.8m in redress to customers who complained about payment protection insurance. This is the highest figure since March 2016 and takes the amount paid since January 2011 to £30bn.
Excluding PPI the number of complaints received by firms was 2.21million, around 13,000 fewer than the previous six months.
After PPI, the next most complained about products are current accounts, with 509,047 complaints and then credit cards with 314,586 complaints.
Christopher Woolard, executive director of strategy and competition at the FCA, said: "Having set a deadline for PPI complaints, we are encouraging consumers to decide whether they want to claim, and if they do, to make their complaint as soon as possible, as many already have.
"We are continuing to monitor and challenge all firms to ensure they maintain the expected standards and are delivering on their commitments to make it easy for people to complain about PPI.
"When PPI is taken out of the mix, the numbers of complaints firms are receiving has remained stable. Firms should be doing all they can to reduce complaints and ensure they are treating customers fairly."
In a statement, Together said: “We take all complaints very seriously and always conduct thorough complaints analysis to ensure we take learnings from individual complaints to improve service for other customers. We also have an ongoing programme of activities to improve customer outcomes, customer satisfaction and to address the causes of these complaints. The home finance data, published by the FCA, relates to our historic Blemain Finance loan book, which is no longer open to new business. Consequently, complaints as a proportion of the diminishing loan book are likely to appear higher than average.
“All of our home finance is currently funded through Together Personal Finance, which has significantly fewer complaints. In addition to complaints analysis, we also track customer satisfaction across the group, including Blemain Finance. Our most recent data shows that over 80% of our customers describe us as being easy to deal with and satisfied with the service they have received, and we will continue to strive to improve customer satisfaction.”
