You have purchased some various sundries at a local hardware store using your credit card. A couple of days later you get an email from the manager of the store stating that you were significantly under-charged, offering to email you the requisite documents, and requesting permission to charge the difference to your card. You check your credit card statement and see that you have been under-charged. You call the store requesting to speak to "the manager" as a way of verifying the legitimacy of the email. It is legitimate.
At this point do you:
- accede to the request,
- simply ignore it,
- contact this person directly and say it is their "tough luck", or
- pursue some other course of action