Save the Children is to pull out of the Isle of Man later this month.
Shop leaders were told by their area manager that it was no longer financially viable to keep Save the Children in the island.
The Isle of Man has actively raised money for Save the Children for 50 years, and was established in 1974.
At one point, the three shops could raise in the region of £150,000 a year for the charity.
Covid disrupted normal trade, with the Save the Children headquarters delaying the re-opening of the shops.
The revenue from the shops in recent times has dropped in comparison to pre-pandemic levels.
Rosemary Walters, one of the vice-presidents of Save the Children in the island, said: ‘Regarding the Save the Children leaving the island, it has come as a complete shock to everyone.
‘So far, we have not been given any information or explanation from Save the Children, so at the moment we are waiting to hear from them.’
Mrs Walters added: ‘Since [two of the original volunteers] Pat and Haley set up the first official fundraising in the early 70s, the island has raised millions of pounds.’
With the money raised, the island has funded four schools in Sri Lanka, following the civil war there, and a neonatal clinic in Rwanda.
Mrs Walters said: ‘We are so proud of what we have done for Save the Children.’
The Isle of Man has also benefited from two projects funded by Save the Children.
One was an anti-bullying scheme, and the other was called FAST- Families and Schools Together, which encouraged parents, particularly who had a poor experience of school in their own childhood, to go to their children’s schools and be involved.
Sue Guest, the shop leader in Ramsey, said: ‘I think it will be greatly missed, we are part of the community, we are not only there for the charity itself, however good it is, but we can sometimes be a bit of a lifeline for the public.
‘You get elderly people and not so elderly people that can get quite lonely and they can come in, have a chat with us – we’re a friendly face and we are known to be a friendly charity.’
Edna Clarke, who volunteered for Save the Children for 40 years, said: ‘Volunteers are devastated, every one of us. We have a loyal group of volunteers and we are all so upset.’
There will be a fashion show in Ramsey tomorrow (Friday) evening, to say goodbye to the charity, and a thank you to all the volunteers.
Edna Clarke, who came up with the idea, said: ‘I thought volunteers never really get a thank you and the other charity shops, Hospice and Age Concern work hard in the town too, so they are also taking part and it will be a little bit of fun.
‘The event will be a thank you to everybody and a goodbye.’
To book a ticket for the event, call Edna on 460867.
There will also be a raffle and refreshments.