Hi.  I am interested in AT&T Prepaid but I have two questions I couldn't find the answers to on AT&T's site. (1) my partner and I both currently have T-Mobile GSM iPhones.  (Mine is an iPhone SE, I forget exactly which model hers is but it's a few years old.)  If we get them unlocked, can we switch

I have been having problems with voice calls since upgrading to iPhone 6 plus. Except for calls to other iPhone users, calls have static, I can't hear the caller on the other end or they can't hear me, the sound breaks up, or the person on the other end sounds like Charlie Brown's teacher. I took my

Microsoft Lumia 640 XL LTE phone --- recently have gotten reports from anyone I call that it sounds like I am in a tunnel or very muffled and hard to hear me.  All pertinent settings related to audio and volume on my phone are maximized, but no one is able to hear me clearly.  Need help fixing this.