The biggest problem I have with cell phone carriers, Verizon Wireless to be specific, is their double billing practices, which is made worse by double talk in their explanation of the charges.
The problem is caused by their billing method, which is that they pre-bill 1 month in advance, which is insane, no other company does this. So when I'm paying for February, I'm actually paying for March, and this is where the double billing comes in. If I make any change to my current plan, I'm billed on my current monthly charges as well as the next because they double bill. Whenever I've called and complained about it, they give me some double talk about billing in advance, and the date it takes effect, it makes absolutely no sense whatsoever. Once I spoke with the tech support's supervisor and got my bill reduced by 2/3s but they won't admit that they're wrong and highly unethical with how they bill people.
The first time I signed up with them I was billed twice because I signed up in the middle of the month! I kid you not, I was billed for May and June at the same time, before I had even used the phone for one month. It's flat out highway robbery the way Verizon and other companies operate.
Ironically scam artists are arrested for this all the time, whether it's a phone scam or a con artist using some type of card trick at a casino, but when phone companies do it to millions of customers on a monthly basis, it's simply routine. It's kind of like the quote by Stalin: "If you kill one person, it's called murder, but if you kill millions it's a statistic." Same principle applies to cell phone companies, they're getting away with murder.