Originally Posted by benjoe
You're lucky and good. The same thing happened to me, and I had photocopied the certificate, as well. When the status of the reservation hadn't changed, I called them a week before the trip. They said I was out-of-luck -- even with the photocopies. Photocopies were no good. They said I should have sent the certificates via certified mail. The best they could do was offer me the opportunity to buy the tickets pre-discount.
Whenever I redeem certs via mail-in, I always have the phone rep. record the cert's promo code and serial number in the comments of the PNR - if the cert goes astray, it can still be applied to your booking with that info.