Hi Rachel, I am looking into this. In the mean time, can you navigate to Settings > Apps > All > Play Store > Clear data ... then restart the phone. Launch the Play Store > Wait unitl prompted to accept the Terms and Condition > Accept when prompted and then retry applying the Gift Card code. Also do check to see if the balance have not changed before proceeding as credit may also have been applied. I will update my answer upon finding more information.
Edit. The following is what the Google Play Store Gift Card troubleshooter has to say: When redeeming a card or code, make sure you enter your code exactly as it appears on your card, receipt, or confirmation, without any spaces or dashes. Please note:
- If your promo code was provided by a third party, please check with the retailer for more details on how to redeem your code.
- If you're still getting this error message after carefully entering the code, please check with the retailer that your card has been activated.
- Promo codes may expire. Please refer to the promotion terms or contact the retailer for more information.