What can come back
Stocked items can be returned within 14 days of purchase for a refund, credit or exchange. Call Packaging Suppliers on +44 (0)208 386 6960 and arrange it. Do not send rolls or sacks back without that call.
Something made or printed to order is covered on the returns page, not by this stocked-item window.
A fault in the delivery
If a defect was not obvious when the supplies arrived, the terms ask for notice within 14 days of discovering it, and no later than 30 days from delivery.
The next order of mailers or kraft is unaffected. It still needs to be in by 3pm.