Found this in the CommBank app under "More to explore" (Looks like it's targeted)
How to claim
- Activate before you spend
- Shop online on the Sennheiser website
- Pay with your eligible CommBank debit Mastercard or credit Mastercard or StepPay
- Get cashback into your account
Expires on the 5th of June at midnight
Payments can't be made with Afterpay, ZipPay or PayPal
Nope….