mobile

Hi, I bought a my HTC one m7 from Amazon US and it turns out the phone was not Factory Unlocked but a phone from puerto rico that was Unlocked with a Carrier unlock code or something like that, the phone came in a sealed box which is why IDK wtf happened, anyways

I was trying to update my rom from the HTC website and it didnt let me because It said I had the wrong model, so I contacted HTC support and they told me what I wrote first.

So my question here is, I cant return the phone because I bought it outside the us but it was from Amazon (I have prime). Can I convert my BRANDED phone to factory unlocked or something? I cant upgrade to lollipop because apparently the carrier this phone had is not upgrading it.

Thanks.