So i ordered legal RC offline and i got my package and there was green tap and a note inside sayong (pursuat to 19CFR145.59 narcotics and or other contraband prohibited from entry to united states have been seized from this mail shopment for appropriate action and disposation under the US customs protection law IS san franscisco phone number 415-782-9220)
they were legal RCs tho? what shoud i do? should i call a lawyer?
First - you don't need a lawyer. You're not in actual trouble. That's just the letter they send when they seize something at customs.
Since it's a legal item - and make sure it is a legal item in your state first - you actually could call them and request they re-evaluate the contents and forward them to you. But you also better have whatever plant you intended to use the RC as food for.
You're best off cutting your loss, and contacting the vendor to see what their policy is about replacing items not received. (You said you ordered it offline, so I don't know how you ordered it to begin with.)
Ask them to include better documentation (MSDS, invoice) of the chemical according to USA shipping laws. It may simply be a matter the substance isn't permitted to be sent in US mail, or you were unaware of its current legal status.