magenta3508791, I don't blame you one bit for the frustration you're expressing. Although I do know some promotions take two bill cycles to appear; the lack of consistency it sounds like you're receiving when you call us to check on your promotion status is a big ball drop on our part, and I don't blame you for being disappointed.
We want you to have clear answers and expectations when you reach out for assistance. Can you please reach out to our T-Force team on Twitter (via DM) or Facebook (via Message)? In those channels we have a secure platform to verify your account and can take a look. This Get the Samsung Galaxy S9 or S9+ and save up to $360 with trade-in promo was a little different than others because unless you purchased from Costco, you wouldn't have used the promotional site to submit for it -- which also means that you're not able to use the promo site to check on it. Please give our teams another shot at getting to the bottom of this!