what should I do ? the package is not reached, the track number is not tracked

[nik_pai]

what should I do ? the package is not reached, the track number is not tracked
the seller writes:

Good morning,
I have never had anyone file a claim against me, if that is what you are asking. I did find out that I can not open a claim with the United States post office until the parcel has been missing for 21 days.

Can you please send me the phone number of the shipping company you are using that I had sent it to you because the post office is telling me it was delivered so I believe they have it and they are not telling you that they have it.

I am sorry this is happening to both of us, I would like to contact the person you had me send it to if you can please get me their phone number.

Thank you

track number 9400109699937270193590