Aus Post Promoted Mother's Day Sales. E.g. 50% off Selected 2XU, $30 off $150 Lorna Jane + More

Got an email from Aus post promoting mothers day related sales. For example:
Store - discount (Promo Code)

Catch of the day - 20% off (LoveMum)
Kogan - Free gift with eligible purchases (AUSPOSTMUM)
Lorna Jane - $30 off $150 spend on full priced items (AUSPOST16)
New Balance - 30% off full priced items (MDAUSPOST16)

I tried it on men's stuff in the 2XU store and it accepted the code but didn't apply a discount.