HR headaches

Anyone had a situation like this? I got a warning about being overdue on a mandatory online training item at work. Apparently this will impact my performance rating and bonus. When I looked into it, the course showed up in my assignment queue labeled "Post-Course Assessment: COURSENAME" with a due date but no Mandatory label.  I probably thought it was a feedback form on something I had completed and disregarded it. It was some type of assessment that leads to a course exemption if you pass (but then why isn't it labeled Pre-Course Assessment?). The same course inexplicably showed a second time in my queue labeled "Due Anytime".  My department head agreed that it was confusing and asked HR to reconsider - but they won't budge!  Additionally, I got a warning about another overdue course where no such course existed among my assignments. When I asked HR, they said it was an error that I should disregard - so who's to say that there was no error in the first episode?

I find this situation pretty difficult to accept, but what can I do? Consult a lawyer?