However, no one else is struck by the fact that someone who is in the business of lending money acknowledges that he has tried to pay 5 times without sufficient funds?
I don't think this is strange. People mostly use these cards to pay for online subscriptions, such as buying game credits or subscribing to Netflix. Some services automatically try to spend the funds from your card when the package expires. If the funds are insufficient, the service keeps trying to renew your subscription until it succeeds. I assume he subscribed to something and turned on the auto-renewal, which triggered multiple attempts to spend the funds from the card. I am sure people do not keep large funds on such cards.
You are correct, @God Of Thunder, and it's not just something that happens with Netflix; almost all subscriptions which we use our card for do try that. Unless you go back and cancel your membership with them or use the payment option and disable the card once it's the due date for your subscription renewal, they will keep on trying to make the payment themselves through the card you have added there even without your permission, and I have been debited for my Netflix subscription renewal even when I no longer use the account again, which is why I have to cancel my membership with them.
You keep reuploading this image to answer the question about card deleting, which you don't have included in your ToS, both on the forum and on your website. What if the customer doesn't log into his or her account over this period? Do you just assume they got the notification and chose to ignore it? And aside from the pop-up and the display each time the customer logs in, do you try reaching them with the warning via the email attached to the account?