"On vacation" makes it sounds like workers were just off "having fun" (which of course is their right), but as your story illustrates, many immigrants are required to leave the US for their visa renewals. To be forced to leave the country and then be barred from return by an sudden change in the rules is the most unjust cruelty.
As an American, I'm deeply ashamed by this. I hope you and your family are able to return home soon. Thank you for sharing your story.