I purchased a R/T first class ticket to DC on Delta and gave them my Alaska mileage number. When the miles posted, I received credit for the outbound trip which was on Delta including bonus miles for first class but my return, which turned out ot be on a Northwest jet, did not credit any bonus miles. I called the mileage plan center and they said to fax my boarding passes and my eticket which I did. They called back the next week and said that my return ticket was not booked in "F." I said I was seated in first class and my eticket says "F" on all portions so how can that be? She said the Northwest segments booked in something other than "F" and i would not get bonus credit. I am close to getting MVP for the year and this is messing up my final miles. Who can I write to for a review of this? Thanks!