1. Tracking number RA686268290CN and RA541682617CN are not valid tracking number. You can verify them here:
http://track-chinapost.com/startairmail.php

2. For parcel RS203076499CN, it's a valid tracking number but I was not able to track that parcel. Sometimes you need to wait up to 10 days before the tracking number gets register into the China Post system.

3. If after 10 days you still can not track the parcel, then contact seller and ask him if he did physically mail the parcel.

4. For your 2 parcels with the tracking number not valid/fake/wrong, you should contact seller and let him know about the tracking number. Depending on the answer of the seller, you could when ever you can open a dispute to get your money back.

Hope this help.