Received an e-mail from nwa.com about a fall cash+miles offer. Since many fares are sky high I though I would take a look at it, but it asks for an E-Certificate (PK057 or PK058--got that far) and a reference code. Usually my WorldPerks number works, but not this time, and I cannot find any "reference code" anywhere in the e-mail or the promo.

Anyone else have this problem? What do I have to type as my "reference code" to get the promo fares+miles?