Back around 2010 we were in a situation where the only viable option for general internet was wireless. We got a Verizon MiFi hotspot and thought it was great. We're frugal with our bandwidth, so the 5 Gb cap didn't really bother us. But one month we did need a bit more and we went over a bit. Going to just under 6 Gb doubled our bill. There was no meter or warning. I called the customer service and they "generously" canceled the charge "this time." I explained the situation and said that if it happened again I'd have to cancel the service. They had no answer.
Two weeks later I got a call from the provider. They had a new service that would text me to warn me I was approaching the cap. Great, right? I explained that the MiFi hotspot isn't a phone and that while it could receive texts, the only way to read them was to disable the wifi and plug it directly into my computer with a USB cable. How often am I supposed to do that?
So I switched to T-mobile who promised that would never happen. They just throttled down to 2G speeds when you hit the cap instead of engaging in usury. OK, that was better. But then my wife landed a job working for an online outfit that required a lot of usage. She was hitting our 10 Gb cap around the 20th of the month and then couldn't work without going to the library to mooch their internet. I went to the T-Mobile store and said, I need 20 Gb per month, how much will that cost? They had no way to sell it to me. I opened my wallet and said "I have money in my hand, please take it from me." The staff spent nearly two hours trying to figure out something. But there was no plan at any price available with a higher cap. They even looked at business plans but those had all kinds of hoops I couldn't jump through as a consumer. I couldn't even open a separate account with a different hotspot because everything was tied to my meatspace ID and the computer knew I was the same person with an existing account.
Much as I hated dealing with the cable company I ended up with a cable modem. It may be capped, but if so at a limit I never come near. There have been the usual run of outages and mishaps with the billing which any cable customer can tell you about, but at least I have enough service to do the shit I need to do.