Just received an email so I screen captured it.
24hrs Only
Terms & Conditions - Spend & Save: Offer applies to full price items only - Spend $80 and receive $20 off, spend $100 and receive $30 off, spend $120 or more and receive $40 off. Offer will be automatically applied at the checkout. Offer excludes sale items, 'Mark Tuckey + Cotton On' products, Cotton On Foundation and Gift Cards. Offer available online only and cottonon.com/AU until midnight AEDT Wednesday 21 October 2015. Cannot be used in conjunction with any other offer.