The shipping company will reach out to you (in my case DHL was used) you pay when it actually goes through customs to get it released. Make sure your contact info is correct when ordering or you may have issues if shipping co can't reach you to pay.
MY KS0 Ultra was JUNK out of the Box too. Turned on but would NOT mine.. It's on its SECOND trip back to the Factory Repair shop. $104 shipping each trip.. First repair did not fix cra p.. . Iceriver is Garbage.