Promotional Trade-In Credit Never Applied to Account?

Literally just had this same issue. It's my fault for not looking at the bill closer until now but I honestly had a few promotions with T-Mobile when we switched from Sprint. I got the text message that our 4 iPhone trade ins were completed and credited but one of the iPhone 7 Plus 128gb weren't eligible for the installment credit because as the main account holder, I chose the BOGO for the 5th line for a free phone. Store associate never mentioned that. He sold me on trade ins for the iPhones with credits for each phone/line. I'd get a free 5th line with a free specific phones only but even that promotion had issues. Got the Apple iPods promotion too and they tried to sell me on the iPad promo too. Why offer any of these promos if the system can't handle it or if the promise isn't going to be kept? They did offer to credit some but we definitely lost out on a lot more. Honestly the only way we'd probably even see a better resolution is when we decide to leave tmobile.