Compare and contrast with a US cell carrier - tmobile for example. In three months they have sent me 3 bills all of which are wildly wrong. There are columns

Compare and contrast with a US cell carrier - tmobile for example. In three months they have sent me 3 bills all of which are wildly wrong. There are columns of numbers and rows of numbers. None of the numbers add up to any of the other numbers. I got charged 6 regulatory fees in two months. There are numerous credits and unexplained charges. (BTW every single "error" has been in their favour.) They just sent me a text message saying my last bill was calculated wrong without further explanation. I'm online only (save the trees etc) and I see it has increased by about 10% without any explanation as to how. When I call them up, there is an automated system you have to say what you want 4 times to which it will say it doesn't understand 4 times, before letting you talk to a person. The person doesn't have caller id and will ask the same question the automated system did (eg last 4 of ssn). After 30 minutes they couldn't even figure out what was going on, and said to call back a day later. Presumably the hope is that someone else will have to work it out. The call a month ago took 90 minutes. It took the rep who worked for them 1h15m to work out what the bill was trying to say. It also turns out that what they show customers and what they show the reps differs. We had established that the final total was wrong, but she couldn't work out what all the numbers were or why they didn't add up to total, or why the total was more than it should be. They eventually gave me a credit I think mainly because everyone was just worn down. And then we get back a further month to when I signed up online. They will not let you select the plan until you pick a SIM card first. They mail you the SIM card. They start charging you the moment their systems accept the new account. This is before the SIM is mailed, before you receive the SIM card in the post (4 days later) and before you actually put it into any device. The reasoning is that you could call up and provision a different SIM card, and you are somehow supposed to deduce that from being forced to pick one and receive it in the mail. It is like they are trying to have the worst customer service possible. Or maybe they are hoping to wear customers out with bogus charges and confusion since these shenanigans are only discovered after the initial trial period is over and you are stuck with the contract. My experience with Verizon Wireless about 10 years ago was somewhat similar except nowhere near the same degree (they only screwed up two months of bills, always in their favour, and quicker/easier to resolve).