Paying back medicaid

My mom passed away last year and she had $1,700 left in the bank. After 30 days I was able to get her money out of the bank with her death certificate and my brothers and I split it up. Almost 6 months later I got a letter from the state telling me that they wanted the $1,700 that had been left in my moms account to repay the $150,000 she got paid in medical expenses while she was on medicaid. I looked into it and found out that since I was on social security myself and I'm the one who took the money out of my moms account that I don't have to pay them the money. At least in my state if you are disabled, on ssi or social security, they can't come after you for the money that you got from a deceased relative.