UK carriers are awful. I had Orange (also part of EE) sell me a new Symbian SE smartphone in 2003 that was broken OUT OF THE BOX. As in, in the store, they couldn't activate it because it wouldn't boot. The rep handed me the broken phone and explained that I would have to send it in to SE for repair, and that my contract started today.
I had an absolute conniption fit, went straight to the manager of the store, and got told that "in this country, we have policies." The manager actually pulled out their policy binder and showed me where it forbade them from replacing a broken device, and then started pulling a "you Americans always think you should just get your way."
In a store where I'd just signed for an expensive new phone and plan.
Obviously, I was unimpressed. So I raised my voice so that everyone in the store could hear me.
"Hi, EVERYONE! This store just signed me up for a new phone and new expensive service agreement, gave me a device right now that was broken out of the box, and then told me it was my problem. I suggest that you find another carrier!"
A couple of people walked out of the store (either due to my story or my tone of voice). The manager demanded I leave and threatened to have me arrested, at which point I invited him to call the police so that I could have them both arrested for their attempt to defraud me by selling me faulty merchandise. He paused.
Then I noted that County Court was just two blocks away, and that I'd be filing a suit and calling on them to testify about their behavior. "This dumb provincial American knows his English law," I said.
At which point he capitulated and gave me another working phone "as a concession."
Unreal. When my contract came up, I couldn't get away from Orange fast enough.
The best thing? All over their store were ear sculptures that said "Orange cares. We listen and we provide excellent customer service."
UK customer service in general is pretty poor compared to other places I've lived, but I can vouch for the awfulness that is Orange (EE).