Sainsbury's has some terms and conditions which may affect some donations. These are visible on their store page here: https://www.giveasyoulive.com/stores/sainsburys
For existing customers, they currently only pay donations on click and collect orders over £40. They do not pay donations on delivery. The terms and conditions change regularly, so it is important to check their Terms and Conditions before making purchases.
If you have complied with Sainsbury's Terms and Conditions and your donations are still missing, you can submit a claim via this link: https://www.giveasyoulive.com/account/claim/list. Any missing claims must be submitted within six months of the order being made.