1. Your parcel was deliver:
2016-09-11 09:34 Post South oil, has been voted

2. Maybe somebody close to the recipient receive the parcel and never told him. Maybe somebody of his entourage got the parcel and never told him.

3. If recipient still denied receiving the parcel, I hope it was a register parcel with a signature. Then what you need to do is ask Germain Post to launch an investigation about the parcel because recipient is telling you he has not receive the parcel.

4. Also if recipient is the seller of an article that you return through the mail, then contact seller and provide him with the full tracking of the parcel here:
China Post Register Air Mail Tracking System
Parcel No.RR085695822DE tracking result
2016-08-25 05:08:00.0 Frankfurt export customs cleared
2016-09-01 10:35:44.0 Beijing Transit Station import customs scan
2016-09-01 14:42:51.0 Beijing Transit Station import customs cleared (domestic transit )
2016-09-06 09:16:03.0 Shenzhen Transit Station import customs scan
2016-09-06 14:52:02.0 Shenzhen Transit Station import customs cleared (domestic transit )
2016-09-08 08:52:51.0 arrive 投递南油 delivery office
2016-09-08 14:07:07.0 投递南油 attempt delivery
2016-09-08 18:57:28.0 投递南油 attempt delivery
2016-09-11 08:54:06.0 投递南油 attempt delivery
2016-09-11 09:03:28.0 投递南油 attempt delivery
2016-09-11 09:34:00.0 投递南油 delivered

5. If seller still denies that he receive the item you bough from him, I'm not sure but maybe you can open a dispute to get your money back. In your dispute just put all contact that you sent to seller about your parcel.

Hope this help.

1. Good to no that the recipient acknowledge the receipt of the parcel.

Thanks