[Pro_SE]

Calling or chatting. Both work just as well. Probably better to call for such a large $ item in my opinion.

Agreed, calling comes across as more direct and I can sound urgent etc. I had another thought-since it's so high value, if there's a signature, what happens if I write John Smith or UPS on it? Can I raise hell with Amazon and challenge that I never signed it?

If you are worried about the signature, just pretend you aren’t in when they come to deliver the item. Then they will hopefully leave it at your door, or drop it off with a neighbour.