DONATION REFUND: Can a registered charity return a gift to a donor?
In most cases, a registered charity cannot return a donor's gift. At law, a gift transfers ownership of the money or other gifted property from the donor to the charity. Once the transfer is made, the charity is obliged to use the gift in carrying out its charitable purposes.
https://www.canada.ca/en/revenue-agency/services/charities-giving/charities/operating-a-registered-charity/receiving-gifts/returning-a-gift-a-donor.html