T-mobile Upgrade Confusion

I’ve been back with T‑Mobile for 2 years, 5 lines for $176/mo. Two weeks ago, a T‑Mobile store out of state told me I could upgrade to the Galaxy S26+ for free with no bill credits. Today, my local store said the opposite, I’d have $200 added to my bill over 24 months. But my sons can upgrade their iPhones to the iPhone 17 for free. When I asked why Samsung requires bill credits but iPhone doesn’t, nobody could explain it. Manager just said the credits “keep you for 2 years.” So now I’ve heard two completely different things. Planning to check Costco and call customer service. Anyone know why the promos are so inconsistent? I’m not trying to raise my bill right now.