I've never seen that before did you order multiple packages? That's pretty fast to get a letter from Customs using tape a long time like a week or so to receive a letter. The good thing is you just six letter and send it over to nap support and they well reship your items.

That's very odd, unless there are multiple packages. I would give it a day or two then contact naps support and work with them to get a replacement sent 

Most likely multiple packages.  Wait and see what get delivered to determine what you're missing.  When you determine what's missing, open a help ticket with naps and they will reship what was seized.  Good luck....

I would open up a ticket with Naps I'm sure they've seen this issue mor than once. 

Yes this is normal not sure how long you've been ordering but when the status shows " Processed through facility ISC New York" for example it really means it just arrived from overseas and is being processed. The only time you know it has gone through ISC customs is when the next updarte on USPS tracking shows " arrived at Queens USPS facility" for example, that is when you know the package has passed through customs. Just go to Napshelp and show them a picture  of the seizure letter  and they will issue you a credit for the purchase. They only give you a one time credit for every purchase that is seized so if it seized on a reattempt it's on you now. You might want to have it delivered to a different address or a PO Box. 

Open a ticket and submit pic of the slip they will take care of you