I sent a letter to Qui Minnan at the following address: Ren Yu Lan, 491 South Chang'an Road, Xi'an 710061,China but my letter was returned to me with the message that my letter could not be delivered, why is that and should I try again?

I finally found a tracker that shows me the whereabouts of a letter I sent over a month ago. Can anybody tell me who I can contact (by phone) to enquire about this. It appears it was sent to the right city, then returned to Beijing for some reason. I need to know which postal company is in charge of delivering it and how I can get in touch.

Fri, Oct 28, 2016 18:56
[Beijing swap Council] has export open split
Thu, Oct 27, 2016 08:19
[Dalian swap Council] has export mutual seal (domestic by turned)
Thu, Oct 27, 2016 08:13
[Dalian swap Council] has export open split
Tue, Oct 25, 2016 13:24
[Dalian Sha he Kou posted Department] has turned
Tue, Oct 25, 2016 07:13
[Dalian Sha he Kou posted Department] is posted
Sat, Oct 22, 2016 13:31
[Dalian Sha he Kou posted Department] throw
Sat, Oct 22, 2016 13:23
[Dalian Sha he Kou posted Department] is posted
Sat, Oct 22, 2016 07:06
[Dalian Sha he Kou posted Department] is posted
Fri, Oct 21, 2016 14:42
[Dalian Sha he Kou posted Department] throw
Fri, Oct 21, 2016 07:10
[Dalian Sha he Kou posted Department] is posted
Thu, Oct 20, 2016 12:55
[ Dalian Sha he Kou posted Department] throw
Thu, Oct 20, 2016 07:08
[Dalian Sha he Kou posted Department] is posted
Wed, Oct 19, 2016 15:02
[Dalian Sha he Kou posted Department] throw
Wed, Oct 19, 2016 07:13
[Dalian Sha he Kou posted Department] is posted
Wed, Oct 19, 2016 07:05
[Dalian Sha he Kou posted Department] is posted
Tue, Oct 18, 2016 10:12
[Dalian Sha he Kou posted Department] throw
Tue, Oct 18, 2016 07:10
[Dalian Sha he Kou posted Department] is posted
Sat, Oct 15, 2016 13:11
[Dalian Sha he Kou posted Department] throw
Sat, Oct 15, 2016 07:00
[Dalian Sha he Kou posted Department] is posted
Fri, Oct 14, 2016 11:13
[Dalian Sha he Kou posted Department] throw
Fri, Oct 14, 2016 06:45
[ Dalian Sha he Kou posted Department] is posted
Thu, Oct 13, 2016 13:57
[Dalian Sha he Kou posted Department] throw
Thu, Oct 13, 2016 06:55
[Dalian Sha he Kou posted Department] is posted
Wed, Oct 12, 2016 10:21
[Dalian Sha he Kou posted Department] throw
Wed, Oct 12, 2016 07:18
[Dalian Sha he Kou posted Department] is posted
Tue, Oct 11, 2016 15:09
[Dalian Sha he Kou posted Department] throw
Tue, Oct 11, 2016 15:09
[Dalian Sha he Kou posted Department] is posted
Mon, Oct 10, 2016 14:10
[Dalian Sha he Kou posted Department] throw
Mon, Oct 10, 2016 07:08
[Dalian Sha he Kou posted Department] is posted
Wed, Oct 05, 2016 09:23
[Dalian Sha he Kou posted Department] throw
Wed, Oct 05, 2016 09:20
[ Dalian Sha he Kou posted Department] is posted
Wed, Oct 05, 2016 07:16
[Dalian Sha he Kou posted Department] is posted
Wed, Oct 05, 2016 07:13
arrived [Dalian Sha he Kou posted Department] posted Council
Tue, Oct 04, 2016 11:22
[Dalian swap Council] has imports mutual seal (domestic by turned)
Tue, Oct 04, 2016 08:30
[Dalian swap Council] has imports open split
Sat, Oct 01, 2016 14:35
[Beijing swap Council] has imports mutual seal (domestic by turned)
Sat, Oct 01, 2016 10:36
[Beijing swap Council] has imports open split
Wed, Sep 28, 2016 06:01
[blue Lee] has export straight seal
Wed, Sep 28, 2016 02:08
left [blue Lee]
Sat, Sep 24, 2016 15:15
[United Kingdom] has received sent

Postage charge for letter to Scancbenz China?