How do I cancel my monthly credit card donation? SU2C Support January 31, 2025 03:27 Updated To cancel your monthly credit card donation don't hesitate to get in touch with Donor Support at donorsupport@su2c.org or by calling 1-800-204-5809. Related articles I have a question about my donation, who do I contact? Is my donation to Stand Up To Cancer tax deductible? What hours are your Donor Support representatives available? Are donations made to my livesteam tax deductible? Are auctions benefitting Stand Up To Cancer allowed?