If you have shopped in-store, purchases made in-store are calculated at the end of each day, so any rewards you are eligible for are sent the next day via email.
If you purchased online, your Perks points and any subsequent vouchers, are added to your account when your order physically leaves the warehouse and is scanned by our delivery partner.
Once the points are added, if you are then eligible for a voucher, this will be emailed to you. Please be sure to check your spam/junk/promotions folders to make sure they haven't landed in there. You can also view valid vouchers by signing up for a shopping account online here. If you already have an online shopping account, you can check your points and vouchers by logging into your account and clicking on "My Perks".