Do you contact the customs office or the carrier first?

I would stop trying to convey how bad it is and start saying what you want them to do.

If it came with a repeat slip, the slip beats every database.

The last ten percent of a taper takes as long as the first ninety. Nobody says so until you are in it.

Same here.

Same shape here, different drug. The thing that helped was documenting the refusal rather than re-arguing it. They refer rather than write.

Sleep first. Bad night, bad day, more symptoms. Fix that before changing anything else.