1. This is were the post Office is:
Address : 1 Shunyuan St, Chaoyang, Beijing, Chine
Téléphone :+86 10 6466 7257

2. This is the full tracking:
Parcel No.RT890689971DE tracking result
2016-04-19 05:53:00.0 Frankfurt export customs cleared
2016-04-26 10:49:00.0 Beijing Transit Station import customs scan
2016-04-26 16:26:44.0 Beijing Transit Station import customs cleared (domestic transit )
2016-04-27 08:58:26.0 Beijing Transit Station import customs scan
2016-04-27 14:12:57.0 Beijing Transit Station import customs cleared (domestic transit )
2016-04-28 17:56:01.0 arrive 三源里 Delivery Office delivery office
2016-04-29 09:03:11.0 三源里 Delivery Office attempt delivery
2016-04-29 16:00:00.0 三源里 Delivery Office delivered

3. I Do no see the parcel stuck at the delivery office above.
It arrive on the:
2016-04-28 17:56:01.0 arrive 三源里 Delivery Office delivery office
It attempted delivery on the:
2016-04-29 09:03:11.0 三源里 Delivery Office attempt delivery
And it was delivered on the:
2016-04-29 16:00:00.0 三源里 Delivery Office delivered

4. If the recipient is telling you that he did not receive the parcel then you should ask Germany DHL Paket to investigate about your parcel.

Hope this help.