Rant!!!:Last March I booked a Amtrak Guest Rewards trip for September from Arizona to Glacier Park and return. All the segments were in deluxe sleepers except for Portland to Glacier Park, which was in a family sleeper, the only sleeper accommodation available at the time.
On August 17th I checked the website to find that a deluxe sleeper had become available. I called Guest Rewards to see if it would be a problem to change the accommodations, and was told that the reservation had been changed, and that I would have to return the PDX-GPK tickets to be exchanged for the deluxe sleeper tickets. I mailed the tickets that afternoon by certified mail, but when I returned home that afternoon I found a message to call Guest Rewards.
I was told that there had been a problem changing the reservation, and that they had to cancel the reservation, but had made a new reservation, and that the new tickets for the entire itinerary would be sent out in the next day's mail. I was told that the existing tickets were canceled, and that I could toss them. (I still have them)
On Wednesday, a week after the tickets were supposed to have been mailed I called to inquire, I was told to call back the next day, which was 7 business days from when the tickets were to have been mailed. I called back the next day and was told that they would send me a new set of tickets by Fed-Ex.
Yesterday I returned home to find a message from a supervisor at Guest Rewards, who asked me to call back because of some "issues" concerning my tickets. When I called back the supervisor had left for the day, but I learned from the agent I talked with that there had been changes in the accommodations on the other segments of the trip. The new reservation has a deluxe sleeper between LAX and PDX, but we have to change bedrooms at Emeryville, the GPK-PDX is now a standard sleeper, and on our PDX-LAX our bedroom has been changed to "A", the least desirable of the deluxe sleepers.
Of course, Guest Rewards is not able to waitlist for a deluxe sleeper should one become available, but I was told that I could keep checking with reservations, and if one became available to put it on hold, and then call Guest Rewards to have them make the change.
My wife asks if they can cancel the reservations we made months ago, why can't they cancel the newer reservations and give us back the accommodations we originally booked. I don't have a good answer for that.
A call to Amtrak reservations revealed that the original reservation was canceled on August 17, but the new reservation wasn't created until August 26, and that the tickets haven't been issued yet! 
Obviously I'm pretty unhappy about the changes, but there doesn't appear to be much I can do, the supervisor is supposed to call me first thing Monday morning.