A man with Alzheimer's has been paying hundreds of pounds a month for "unnecessary" utilities and services, his niece has claimed.
Rachel Holdsworth says her uncle, 72, pays bills, including £110 for a Sky TV and phone package, £120 for gas and electric and £35 for boiler servicing.
She said she realised he was making the "unnecessarily large payments" while helping with his finances.
Sky has apologised and said it hoped to find the best deal for her uncle.
It said while there was no error with the bill Ms Holdsworth had been given the wrong information about accessing her uncle's account.
Ms Holdsworth told BBC Radio 5 live her uncle, who lives in Leeds, was diagnosed with Alzheimer's two years ago.
She said, along with her mother, she had recently been given access to his bank accounts and had discovered the various payments, including to Sky.
However Ms Holdsworth said she then faced difficulty accessing his Sky account as she did not have the necessary password.
"He was paying £110 a month to Sky," she added.
"We looked at that and thought this can't just be for TV he must have something that's unnecessary and so we tried to get access to his account.
"My first point of contact with them really was just to say 'what possible package could he have theoretically that would come to £100 a month?'
"Then we were asking 'how do we get access? How do we find out what he does have?' and we were told that without his account password there was no way.
"Now, he's got Alzheimer's and there's no way he's going to remember his account password."
'Unethical and unfair'
Ms Holdsworth shared her progress with Sky on Twitter and received hundreds of messages of support from people with similar experiences.
A spokeswoman for Sky said Ms Holdsworth's uncle had taken out a package deal four years ago but not made any changes or upgrades.
"We're sorry for the problems Mrs Holdsworth experienced trying to access her uncle's account details," she said.
"We'll now work with Mrs Holdsworth to ensure he is on the best package for his needs."
Ms Holdsworth said she believed her uncle's energy bills were the result of "a legacy tariff from when privatisation happened and he never thought to get any kind of discount".
Regarding the boiler maintenance payments she said her uncle "lives in a council house so it's all covered by his rent".
She later posted on Twitter: "As an aside, I believe that any company whose charging policy relies on the customer to actively chose a tariff that doesn't rinse them is unethical and unfairly penalises vulnerable people."
Gavin Terry, policy manager at Alzheimer's Society, said it was important for staff to be trained to spot the signs of vulnerability "so they can speak to customers appropriately and advise on deals that meet their needs".
"Sadly we hear all too often about instances of people with dementia paying through the nose for services, and occasionally even being subject to deliberate exploitation, across a whole range of industries," he added.