Medicaid error

My son (9) no longer qualifies for Medicaid because of an increase in our income (as of 4/1/2003). Benefits should have been suspended on 9/1/02, but due to an administrative error he was not removed from the program. I do not dispute the suspension.

The letter explicitly states it was an administrative error. The social worker explains they were "overworked" and had not been able to catch up until now.

But now I just received a bill from Medicaid for over $400 for benefits payed to medicaid providers from 09/02 to 03/03. If I had known of this suspension I would have either applied for Florida Kids or I would have included him in my employers insurance plan.

Any thoughts? Do you think there is any possibility of avoiding this payment?