The mail is, IMHE, very reliable.

Usually, someone is stealing the mail from your box after delivery or there is some other problem. Do you have a locking mailbox? Have you considered a P.O. Box rental (much more secure for card delivery). One card might get lost, two, I'd start to wonder.

In any event, if it were me, I would not close the account, or even mention it. This is not the way to get cooperation from a credit card issuer.

You sound a bit testy--not that I blame you. Relax and work with the card company--and keep getting those miles.

PS I think the 75K AA bonus offer for Citi cards has been revived (check the the thread on that offer). Apply for the new card and after it comes think about closing the old account. Maybe use a PO Box address for the new card to be sent to?