How to get back the invalid coupons of group members?

You can retrieve the voucher containing invalid group oil in the following ways:

1. Check the voucher details on the group friend platform, including the validity period and usage rules, to see if it meets the usage conditions.

2. If the validity period of the coupon has not expired, you can contact the customer service of the group members and provide the relevant information of the coupon to the customer service, so that the customer service can help find the reason and deal with it.

3. If the validity period of the coupon has expired, you can try to contact the merchant to see if you can extend the validity period of the coupon or reissue a coupon.

4. If the above methods fail to solve the problem, you can complain to the official of PetroChina and let the official intervene.

In short, if you encounter the failure of the group oil coupon, you should contact customer service or merchants in time to solve the problem and avoid unnecessary losses.