Given the age of the Note 4, this must be an insurance, not warranty claim. Insurance is from Asurion and they can’t send a phone they don’t have.  You do have the right to a cash settlement from Asurion, ask for it and buy a new or mint Note 4 off eBay. 

BTW, it seems the claim was entered wrong or they wouldn’t be trying to replace with an S4, then S7. Make sure the IMEI is fixed so you get the right settlement