Why won't AT&T unlock my phone?

That’s news to me. I’ve never heard that any of the free replacement phones they provided customers couldn’t be unlocked. What reason do they give you for denying the unlock request? More than likely it is some snafu due to them being refurbished phones, not that they can’t be unlocked. An FCC complaint will probably get them unlocked. So just about every carrier is offering a trade in deal on new phones. Why not trade them in to whatever carrier you are considering moving to? 

I've never heard of it happening, but to me it makes sense that AT&T wouldn't want you to use the free phone they gave you on a different provider. Basically, it's free as long as you use AT&T. 

In any case, I agree that a BBB or FCC complaint will probably get you in touch with someone who can get the phone unlocked. 

Thank you both for your advice. I followed your suggestions. I will be interested to see if the FCC complaint is effective. At any rate, we have taken advantage of end of the year deals and are moving on. 

Update. I filed an FCC Complaint and was put in contact with the Office of the President! Thought for sure that would get results, but sadly AT&T is still giving me the run around. Now they are telling me that "AT&T will not be able to obtain the unlock  for the older devices made by the manufacturer that no longer has an agreement with AT&T mobility." Huh? The phone is a Samsung Galaxy 9+. How can they not have an agreement with Samsung? What bothers me the most is the waste. What am I supposed to do with this useless phone? It's a perfectly good phone AT&T has made unusable. I am so annoyed with this company. 

Hello

Our team says 

If we don't approve your request, it's probably because your device isn't eligible to be unlocked. Review the list of eligibility requirements. If your device isn't eligible to be unlocked, and you're traveling abroad, choose an AT&T International Plan.

So just keep patience.

They're saying they no longer have support from Samsung to get unlock codes for that particular model. It's common with older model phones. I'm not familiar enough with Samsungs to know if that makes sense in this case. 

If you don't want it donate it, sell it to an AT&T customer, or throw it away. 

It is eligible to be unlocked and you don't want to get me started on what a scam the AT&T International plan is. Can I donate it? Isn't it useless? I'm not interested in selling nor in adding to the toxic waste dump. I simply do not believe they cannot unlock these phones. However, I do appreciate you trying to help.