From next month, Tamba Park memberships will no longer be valid - because the attraction says they're too cheap for it to improve its offering.
Tamba says the decision to axe annual memberships "wasn't an easy one, but is the right one for the future of the park."
Families of up to five have been paying £120 a year to enter the park, but the owner, Jonathan Ruff, says that pricing was "a mistake on their part" and that ending memberships was the only way to fix it.
Customers with current memberships will be refunded after they become invalid on Friday 1 February.
Mr Ruff says it's part of a 12-month plan of changes to the park, which also includes scrapping additional charges for things like boats, crazy golf and trampolines.
Islanders disappointed with the decision have taken to the attraction's Facebook page - with many questioning why the membership fee wasn't just revised, and saying they'll visit far less often having to pay each time.
Others defended the change, saying it's important Tamba Park is able to continue operating to provide something for children to do in the island.
This morning, Mr Ruff has been meeting with customers at the park to answer their questions:
He's revealed plans to "create a huge, new indoor soft play area for all ages" as well as an entertainment stage for live acts.