At this point, what I can say is write them as I explained before if it is some sort of error, schedule an InfoPass, and prepare for a re-test. At least one of all three has to pay off guaranteed because it really does not make any sense to pass a test and receive a letter to retest no matter how many people have received this before. Logically, nobody should receive such a letter to retest something they already confirmed you passed even if its because you had to mail in a requirement that has nothing to do with the civics test or anything else that they couldn't have asked you at the original interview.
Thanks jayoa. I am going to do both infopass and write them as well. I will post here what I find. I must say this is painful.