Best UK mobile provider for my situation?

• I am in the UK. I live in Plymouth. My one year Vodafone contract is finally up and I hate them with a passion. I'd like to switch, but as a still relatively new ex-pat I don't know who to switch to. Can you recommend a provider to me based on my requirements inside? I have an iPhone 5. I mostly use it for data - work email, personal email, navigation, texting, reading Metafilter on the trains, personal hotspot when I need to connect my laptop while I'm on the go. I live in Plymouth and mostly travel around the southwest/south, though I occasionally go to London. I keep my UK SIM in for travel within Europe, but swap to a US SIM when I'm in that country. Work takes me to other (non-European) countries in which I usually just have them pay the international roaming for my UK SIM. I don't much care about 4G since I sincerely doubt there's even 4G in most of the places I spend my time in. 3G is usually hard enough. Things I hate about Vodafone: (1) I've traveled internationally on a monthly basis for the last year. For the first eight months, every single time I was out of the country, they'd cut off my data, saying I'd reached a cap. Twice they cut off my voice too (but required a phone call to re-enable it, because that makes sense?) This kept happening despite me asking every single time to remove any caps. The only reason it hasn't happened in the last few months is that I've mostly only been traveling to the US and I have a dedicated SIM there now. This is infuriating, interferes with my ability to do my job, and shows some pretty crap customer service. Not cool. Don't want this any more. (2) No visual voice mail. Didn't realize how attached I'd grown to it until I didn't have it. I would like visual voice mail back please. I think O2 might be the only ones in the UK who do this? Is that still accurate? (3) Unreliable delivery and notification of voice mails. There are some I never get at all. (4) Same for text messages. (5) I get a "robot voice" from callers occasionally where the beginning and ends of words are clipped or weirdly digitized. I haven't been able to narrow down any particular combination of providers (sometimes it happens with landlines) but it is typically always from the same people, such as my husband. It doesn't happen when I'm calling them on the same handset with the US SIM so I'm blaming it on the provider. I would like not to have robot voices, particularly when I'm being called by someone for work. I don't really care about any particular plans or rates or contracts; I'm happy enough to talk to people in the stores about that. What I really want is a provider that doesn't suck, and I'm hoping you can point me toward the right one. Who has the reputation as the least-terrible mobile provider in the UK?

• Answer:

  They're all capable of acting like a tax on modern living rather than allowing a provider/customer relationship, frankly. Most people seem to decide purely on local coverage and signal strength now the models are pretty much interchangeable between operators. You could try making friends with a permanent staff member at a bigger Vodafone store if there is one - there are usually one or two on the management route who aren't just commission sharks. A lot of the smaller ones seems to be franchises of sorts, and all billing is central so they don't seem to able to help much. They might be able to explain what's going on with the limit caps though.