A woman who fled the Grenfell Tower fire found she was still having rent deducted for her wrecked flat by the council, a campaigner said.
Yvette Williams, a coordinator for Justice 4 Grenfell, said the survivor made the discovery when she obtained a new bank card and saw her statement.
A Tory Kensington and Chelsea councillor said she was "very sorry to hear" the claims.
Catherine Faulks stressed she was "not saying it's a tiny thing", and acknowledged it would be very upsetting for the affected person, but insisted the council is providing a "a lot of hand-holding" for survivors, including assigning an individual social worker to each family.
Ms Williams said she received a call from the distressed survivor on Friday.
"She came to me and said she had just got her bank card and that she went and looked at her bank statement and they had deducted rent for Grenfell Tower," Ms Williams told the Press Association.
"It is, you would think, a simple process (to fix) as it can be done on a computer.
"It is quite clear that whatever is supposed to be happening down there isn't happening - it is about what checks and balances are in place there.
"Of course she is distressed, we have all seen the tower and what it looks like, everyone is living there."
Asked if the survivor had raised her concerns with the council, Ms Williams added: "She hasn't. She has lost her home, she has lost everything."
Responding, Ms Faulks told BBC Radio 4's Today programme: "I'm very sorry to hear that and I can understand that's very distressing."
Asked why the council had not addressed such an "obvious" issue, she replied: "Oh come on, I'm not saying it's a tiny thing, for them it's a huge thing and it's very upsetting.
"But the council are in the process of trying to house 400 people, they have got people in hotels, they have put a social worker for every single family, who is triaging them into a wraparound service.
"I'm very sorry to hear that that happened but that person, if it's happened, will have a one person connection to go to explain that's happened who will help them sort it out.
"I know you're hearing a lot of noise about 'nothing's happening', but actually on the ground there is a lot of hand-holding going on.
"And I haven't yet heard any of the media interview or talk to somebody who has received really the excellent services we have been providing."
In a later statement, a council spokesman said: "We are very sorry if this has happened and we are working to find out who has been affected so we can offer reassurance and an immediate refund.
"To the best of our knowledge the rent charges for Grenfell Tower and Grenfell Walk were stopped.
"But if anyone has had money inadvertently taken as part of a direct debit or standing order we will make arrangements to have it immediately refunded."