The charity called out the FCA over three areas, savings mortgages and home insurance.
On savings it said the regulator should “confirm its proposal to introduce a basic savings rate, which they estimate will save customers a net £300 million a year”.
And, on mortgages, it said: “The FCA should require firms to put vulnerable and low-income customers on to better value mortgage deals.”
Ofcom was also criticised over mobile phone and broadband contracts.
Gillian Guy, chief executive of Citizens Advice, said: “We’re disappointed that a lack of action from regulators means customers continue to be penalised simply for being loyal to their provider.
“In its response to our super-complaint the CMA set out ambitious recommendations for tackling the loyalty penalty.
“But it seems little progress has been made by the regulators within the first six months.
“This is not good enough.
“The FCA and Ofcom need to urgently set out their plans for tackling this systematic scam.”
Responding, Christopher Woolard, executive director of strategy and competition at the FCA, said: “Before the CMA published its super-complaint response last year, we had already begun work in the mortgages, cash savings and general insurance markets.
“Ensuring that markets work well for longstanding and vulnerable consumers continues to be a priority for us and the loyalty penalty is a serious issue.
“We will continue to work closely with the CMA and other regulators on the recommendations relevant to us.”
The Government has pledged to strengthen the Competition and Markets Authority (CMA) to stop firms ripping off loyal customers.
Prime Minister Theresa May said: “For far too long, many big companies have been getting away with harmful trading practices which lead to poor services and confusion among customers who have parted with their hard-earned cash.
“The system as it stands not only lets consumers down, but it also lets down the vast majority of businesses who play by the rules.
“It is high time this came to an end, and today we are confirming our intention to give much stronger powers to the CMA, to strengthen the sanctions available and to give customers the protection they deserve against firms who want to rip them off.”