Robert,
The issue is what did you pay for the trips? I'm guessing since it was a Hiawatha trip, that you're out of luck. However, if your trips cost more than $50, then you are owed points. I quote from the TOC:
Except as provided in this Section, Members who provide their Membership Number at the time of ticket purchase will earn 2 Points for every $1 spent on Amtrak travel, a minimum of 100 Points for each trip. A maximum of two roundtrips or four one-way trips, per member, per day will be allowed to earn points under the 100 point minimum per trip rule. Any trips subsequent to the maximum of two roundtrips or four one-ways, per member, per day will receive 2 Points for every $1 if the trips point value exceeds 100 points.
I bolded the most important part. That comes from rule #4 in section C of the rules found
here on the AGR site.
Now many promotions, including the current Spring/NTD promo also preclude paying out the double/triple points on more than 4 one ways/2 round trips. But again, under all circumstances you are entitled to the typical base points of 2 X the dollar amount if the amount for the ticket was over $50.
Why they don't pay points on the under $50's I'm not quite sure, although I suspect that it comes down to their inability to get the computer to apply the multiplication rule rather than the minimum rule.