Thank you for contacting the GiffGaff Community. Hopefully the following information will help to assist you further.
Before the payback points are paid out you will need to select on how you want them paid out. The points can be claimed here https://giffgaff.com/profile/choose-payback-method as cash (Paypal £10 minimum required), airtime credit or you can donate to charity.
Cash: This is paid via PayPal Instant Payment, you will need to add your PayPal email address (for your active PayPal account) via the Payback widget. You can only select cash if you've earned at least 1,000 Payback points. You will not be charged a fee by PayPal to receive it.
Credit: Your Payback points will be added to your account balance as airtime credit.
Charity *: This goes to the charities chosen by GiffGaff members. The total amount donated by all giffgaff members will be matched by giffgaff - pound for pound.