Sent a package home via EMS, tracking shows “Returned to Sender”

Sent a box on March 31st via EMS Air, decided to check tracking now and I see it shows Returned to Sender since a few hours ago. Don't know what I did wrong, i guess I will find out once they return it to me, but they must have had a good reason to not accept it. Can I get a refund on shipping I paid for, or do I have to pay again after sorting out the issue they had with it? First time this is happening to me.

by drafthard