Here's another mail story. I didn't receive a bill from my Chase Card for December. I went to the store in early January and the clerk at checkout announced loudly "your card is declined."
I called Chase, been their customer for 27 years. No, was their response, we sent the bill, you owe us money plus late fees until the card will be restored. Asked for a copy of the bill, which I never received. Ten days later, they had not received my check. So I sent them another, which they got. Then they got the first check I sent. Now they have been paid twice.
In late January, they said they would send me a refund, but they wouldn't put it back in my account. So far, no refund received. I may never see that money.