You may know otherwise, but in our experience there has been only one case where a white slip was issued, it was re-affirmed, and the petition sent back to GUZ, where it was approved. All this was because GUZ didn't "believe" that they would get married within 90 days. If the visa officer says you "don't have a valid relationship", then, by golly (and law), you don't have a valid relationship - UNTIL you file a new petition. Perhaps your efforts will help toward that end. Only the VO has had an opportunity to talk to your SO - the USCIS won't.