If your Cashback withdrawal status is "Paid", kindly do refer the below screenshot where to request for the Remittance Advice proof of payment. Please do note, you may only request for the Remittance Advice within 30 days from your withdrawal request date:
Click on "Get proof of transfer". You will receive your remittance advice in your email within 24 hours.
Please contact our friendly HappyBag bot here if you have any further concerns and we will be at your assistance.