Moore told Fairfax her mother had become so distressed she called her in a panic one morning at 6am.
"I am the one who usually calls her, so that was the first shock," said Moore. "She sounded distressed, absolutely panic-struck. I actually thought someone had died."
The charities include the Cancer Society and SPCA. Both said they immediately stopped the letters once informed of the situation.
The Cancer Society added, "We don't want to take donations from those who didn't intend or genuinely want to donate to us. If anybody has concerns about any matter with the Cancer Society, you can contact us and we will work with you to rectify."
Moore immediately asked the charities to remove her mother from their mailing lists, Fairfax reported.
"The trouble is once someone gives them money they just bombard you with requests and appeals. I have no idea how much she has paid so far," she said. "The Cancer Society was the worse, they kept sending her letters even when I asked them to stop."
Moore, who lives in Auckland, said her mother had been sent a letter from the SPCA with a power bill inside to show how much their costs have risen.
"It looked like a genuine bill. I mean at first even I was confused as to why mum had a $5900 bill," she told Fairfax.
It turned out the bill was for a promotional campaign, but Moore said her mother struggled to understand the concept.
The donations had been happening for about two months, she said.
Her mother had donated at least $200 in just one week, but Moore is unsure of what other payments were made to the charities.
Age Concern national president Peter Oettli told the Herald that it was hard for charity organisations to know people's mental well being when they send out requests.
However, once informed they should cease with their requests immediately, he said.
"I think that any organisation that solicits for funds has a responsibility to make sure that they receive them ethically. It clearly is impossible for an organisation that circularises a section of the population to know who has dementia and who doesn't. But if they are advised that somebody is no longer able to make decisions about how to dispose of their assets they must immediately stop."
Oettli advised elderly people who became confused or unsure about making donations to ask a "trusted person" for advice. Age Concern would also be happy to help, he said.
Meanwhile, Greypower national president Tom O'Connor says the persistent targeting of elderly people for money is a form of elder abuse.
He said he had heard of other similar cases where elderly, vulnerable, people had been targeted by charities.
"Some charities have become almost predatory in their drive for more money and while they usually work for good causes this can be a form of elder abuse."
O'Connor said while most people get regular unsolicited advertising and begging letters in their mail and most know how to deal with them.
"Some are genuine charities, others are scams under the title of surveys or bogus lotteries," he said.
The chief executive of the Auckland Northland division of the Cancer Society, John Loof, would not discuss individual donors for privacy reasons, but said the organisation did not 'hound' anyone for money.
"The Cancer Society only wants to accept donations that are genuinely intended to help fund cancer research and patient support. We are in the business of helping people, people are at the heart of what we do, and it's in our interests to ensure people get the best experience from us, be they a donor, volunteer or patient."
Amanda Midgen, chief executive of the SPCA, also confirmed that the elderly woman had been immediately removed from their mailing list when the charity was notified.
"We empathise with this family and in a case like this our policy is to always take all appropriate steps to make sure the situation is resolved."
The actions of the charities have been no surprise to some Herald readers.
One Auckland woman says her 88-year-old mother lives alone and is constantly getting phone calls from charities asking for donations.
"She has real trouble saying no to them. I can't believe how she has ended up on these databases as we don't get any. She is of the opinion that everyone gets these calls."
Another woman, whose mother lived in rural Southland, said she had a similar experience in the early 2000s when her mother was repeatedly called on Sunday mornings asking for more donations.
She said her mother understood it to be a one-time donation.
"They persisted in calling, repeatedly, when my mother had no idea why she had been singled out, except that as she had been singled out, she was somehow obliged. It took some very strong language to bring these people to desist."
An Auckland woman felt for Jan Moore as she had been shocked at the number of requests her 89-year-old father received from high profile charities after she moved in with him.
"My father was aged 89 at the time I moved in and was rapidly losing his eyesight, so paying attention to details such as the date of his last donation was difficult. He has given to charities all his life but I believe that he had no idea that the same charities were asking him for money again and again, often in the space of only a few weeks."
"It seemed that no sooner had my father put a donation in the mail than another request would arrive ... I believe elderly people are particularly vulnerable to getting on to mailing lists in this way, as they are more often home during the day to receive these calls."
