When upgrading at Sam's Club or Costco do they confirm what promo code is being applied?

I was attempting to upgrade today and the kiosk said they can't confirm or apply promo codes and that they are automatically done.

None of the documents they wanted me to sign had a promo code or any indication of a trade in.

I didn't really get the warm and fuzzies from that.

Hi,

Can someone tell me which offers can actually be combined with Keep and Switch at Sam’s club? The store employee told me the $200 tmobile gift card and $150 Sam’s club gift card would apply with Byod port from AT&T but T force on twitter told me neither and only a $75 Sam’s club gift card would apply with Keep and switch. The t mobile kiosk at Sam’s didn’t have the promo ads or fine print up since they just opened and the employee lied bc it’s contradicts what tforce on twitter told me. Tforce was the one to send me this link to Sam’s club t mobile offers https://www.samsclub.com/content/tmobile and said I’d get $75 Sam’s gift card for Byod port in along with keep and switch but I don’t see that anywhere on the fine print on the website. Can someone tell me what actually combines and works before I get bait and switched afterwards? The site has no mention of the $75 Sam’s card though tforce mentioned it and the store rep was not helpful/trustworthy.