Was sent the wrong phone and now am forced to pay $900 for a phone I never wanted.

a) a $6/month deal would have been a trade in deal.  Did you ship a trade in within 30 days of purchase?

b) AT&T didn't control your travel plans.  If your travel conflicted with the 14 day return period, then perhaps you shouldn't have purchased the phone at that time.  Their 14 day policy is published, was available when you purchased the phone, etc.

c) If I buy a car, then park it in my garage, the bank will still want their payments.  Your phone is no different.

Almost all of AT&T’s “cheap” phone deals involve monthly offsetting credits on your bill over the 36 months of the installments.  Check your offer to see if this isn’t the case (it’s usually in an asterisked footnote).  It should also say that it takes 2-3 bill cycles for the credits to appear.  In your case, your monthly bill would have shown $24 for the phone, with a $18 bill credit, once the credits started.  It seems like you didn’t wait long enough for the credits to start.

Regarding the return period, it’s 14 days, not 16 days.  That’s a risk you take when you order something while you’re somewhere else and can’t check on it for a while.  You may as well open and activate the phone.  It’s unlikely that they’ll take it back.  You’re paying for it anyway.

This was probably for the no trade in required promo att has occasionally. The op didn’t say what phone he received. Nor whether is on a qualified plan. Any credits would be 2 or 3 billing cycles later. 

A) The deal wasn’t for a trade in or I would’ve gotten the phone at the time and used it while I was out of state. A buddy of mine did the same deal for him, his wife, and their kid. Nobody had to trade a phone in.

B) At the store they didn’t mention anything about a return window and even if they had. How would I have assumed that they would (Edited per community guidelines) up so bad that, not only would they send me the wrong phone, but they would also not apply the promotional deal that I literally went there for the sole reason of? It’s not like there was miscommunication. I talked to them about it for an hour and a half. That’s not only thing they (Edited per community guidelines)ed up. It was just the biggest. They also asked me if I wanted the protection plan. I said no. They put in on my bill. I was asked about AT&T next up. I said no. They put it on my bill.

C) If I buy a car, I’m driving it off the lot before it goes in the garage, am I not? So obviously at that point it’s a done deal. 

@Grim What phone did you get?

@kevink They sent the IPhone 15 instead of the 15 Plus. but I'm legally blind in one eye so I never would've gotten the smaller phone. At this point I'd rather keep using my XS Max so I can actually see it.

@kevink Also I already talked to them and they're not crediting me for anything because the deal was for the 15 Plus and they sent the 15. And because the promotional deal is no longer available anyway so they just wouldn't be able to do it regardless apparently.

So get this. I called the actual store that messed up. And they're allowing me to send the phone back to them directly so they can send me the correct phone. And somehow, magically, they can give me the promotion still even though the actual AT&T company couldn't do ANYTHING.

Yeah, that's quite a bit sus.  I'd carry the phone to that store, make sure you walk out with the phone you intend to, and get documentation of everything they're going to do for you. 

Because at this point I'm afraid the phone you send them is going to get "lost in the mail" (wink, wink, nudge, nudge) and they're not going to be able to do anything for you once that happens.

What store would that be?  It wouldn't happen to actually be an Authorized Retailer would it?

@Grim I agree with @JefferMC that you need to get and save all the paperwork along with receipt for return.