I'd be willing to place a moderate amount of money on this scenario, since I've seen it so very many times before.
The information is in the materials they were sent, probably on their website, and available in about six different places. However, the poster failed to read any of it and expected someone to sit down with her and talk her through the process. It being the busiest time of the year for HR, they didn't have time to do one-on-one sit-downs with employees to tell them information they could read on their own. Therefore, she was "not told" and HR "didn't do their jobs".
Well, pooh on her then. It's not HR's job to provide spoon feeding. There is such a thing as personal responsibility and reading the material you're sent.
We put in big red letters on the election forms, had pop-up windows with the information on the online enrollment screens, and sent out special emails directly telling people that dependent care FSA's are for daycare, NOT for medical expenses for dependents. It's on our website at least twice; it's in the open enrollment materials, and also in the new hire materials. But when we sent out an email saying, "If you elected a dependent care FSA thinking it was for dependent's medical expenses, call us before the new plan year starts so you can fix it" we got at least 50 calls.
At least our OP got that much.