If you paid by credit card request a charge back.
In the USA, lasers are controlled by the FDA (medical and industrial) and should have a license number to be imported. In most cases this isn't an issue with our "kits" but as you found it can occasionally be a problem.
When I purchased my 40W CO2 it got impounded by customs (also shipped by DHL) but was released after I faxed them the certificate showing class IV approval and the form linked below. Of course that actually had one as it uses interlocks and has a protective housing.https://www.fda.gov/downloads/AboutFDA/ReportsManualsForms/Forms/UCM080778.pdf
In my case DHL were fairly helpful and worked to clear the unit from customs and minimize duty (I think I had to pay around $60 but the unit was much more expensive).
Good luck, I hope you can resolve it and get a (very) late Christmas present.