Once your voucher expires you can apply for 80% credit in Points.
To apply for your credit, log into your account, click "My Vouchers" and then Not Used.
You will see a button beside your voucher that will allow you to apply for the credit.
Click the button to claim your credit.
Please note, you have only 6 Months after your voucher has expired to submit your refund request.
Once you have applied for your refund, the Points will be applied to your account within 2 weeks.