AT&T, I think back when I had their service a few years ago, both for business and private phones, in Southern California, the Bay area, and the Pacific Northwest. I hated, literally hated it, but I had them for several years, 8 to be exact, and I thought that was just the way cellular service was. Poor connections, dropped calls, plain and simple lack of service in so many places, and forget about customer service. I would rate their customer service as the very worst I have ever encountered, anywhere! A friend of mine kept laughing at me....kept telling me I was an idiot and should switch to Verison. Finally switched after my last 3 hour (yes 3 hours most of it on hold) fiasco with customer service at AT&T.
I cannot believe I ever put up with AT&T as long as I did. Maybe they are better now than they were 2 or 3 years ago. I sure won't be giving them another try though anytime soon I can tell you that.