Everyone gets notifications. People just make shit up when they can't pay their bills. Letters are recorded when post dates and calls recorded.

I'm not saying an accident can't happen, but very few people are missing payments because nobody called. And most of them will be on account open.

Credit card companies are not going to close your account because you're making minimum payments. That is exactly what they want. I feel like we're missing some context.

That how amex works. You pay in full. You probably went over your pay over time limit. You can only roll a small portion over to next month. The rest is intended to be paid in full.

And discover did no such thing. A bank can absolutely not just say you owe the entire balance in full. I very much doubt your understanding of what happened there.