PDPM ARD

Resident admitted in March with supposedly 100 days of Medicare available. Set ARD for day 8, completed and transmitted the MDS. Resident had 3 MLOAs - upon return for each one - we did a five day on day 1-8. We just found out a couple of weeks ago that the resident actually only had 3 days of Medicare available when he initially came to us!! Yes - someone dropped the ball (that's another story entirely) but is there anything we can do now to get payment for at least the first 3 days? I'm thinking not but my billing office wants to be sure. 

Thank you!