Hi Alejandra,

From the tracking result, it seems all your three parcels have been stuck in Kawasaki and detained by Japan custom. I think you should ask for compensation from China Post, but I'm not sure if you could get. As far as I know, you should contact them within three months if you find the parcel is lost. It has been over 4 months.

Tracking result for CP321066252CN:
2016-04-22 09:15 -- Kawasaki, the transfer of customs
2016-04-21 11:27 -- Japan Kawasaki, reach the Exchange Bureau
2016-04-03 14:53 -- Shanghai Exchange Bureau, have been exported directly
2016-04-03 07:16 -- Shanghai Exchange Bureau, have been exported to open
2016-04-01 10:16 -- Exchange Bureau of Hangzhou, have been exported to each other (internal transit)
2016-04-01 09:03 -- Exchange Bureau in Hangzhou, has been exported to open
2016-03-31 18:46 -- Xiasha, Hangzhou City Branch, left, and the next stop "Center of Hangzhou"
2016-03-31 18:24 -- Xiasha, Hangzhou City Branch,
2016-03-31 16:49 -- Hangzhou Xiasha higher education has been accepted


Tracking result for CP321066323CN:
2016-05-13 09:15 -- Kawasaki, the transfer of customs
2016-05-12 11:40 -- Japan Kawasaki, reach the Exchange Bureau
2016-04-25 12:56 -- Courier, has been exported
2016-04-25 08:06 -- Shanghai Exchange Bureau, have been exported to open
2016-04-23 09:46 -- Exchange Bureau of Hangzhou, have been exported to each other (internal transit)
2016-04-23 08:57 -- Exchange Bureau in Hangzhou, has been exported to open
2016-04-22 18:54 -- Xiasha, Hangzhou City Branch, left, and the next stop "Center of Hangzhou"
2016-04-22 18:23 -- Xiasha, Hangzhou City Branch,
2016-04-22 15:57 -- Hangzhou Xiasha higher education has been accepted

Tracking result for CP321066411CN:
2016-06-03 09:15 -- Kawasaki, the transfer of customs
2016-06-02 10:40 -- Japan Kawasaki, reach the Exchange Bureau
2016-05-16 12:13 -- Shanghai Exchange Bureau, have been exported directly
2016-05-16 07:16 -- Shanghai Exchange Bureau, have been exported to open
2016-05-14 09:32 -- Exchange Bureau of Hangzhou, have been exported to each other (internal transit)
2016-05-14 08:27 -- Exchange Bureau in Hangzhou, has been exported to open
2016-05-13 18:35 -- Xiasha, Hangzhou City Branch, left, and the next stop "Center of Hangzhou"
2016-05-13 17:58 -- Xiasha, Hangzhou City Branch,
2016-05-13 16:01 -- Hangzhou Xiasha higher education has been accepted

I tried contacting japan Post several month ago but they told me they have no information.

Thank you anyway.

Then, you should contact China Post to see if they could give you a reasonable explaination.

Do you know how can I contact them?

Call +86 10 11183 if you are outside China. Then, press 8 for English service.