Can I keep this money from the Insurance company?

I was in an accident where it was the other driver's fault (did not stop at a Stop sign) and my car was smashed and I was brushed a bit, so the other party's insurance company gave me a settlement of $8,000 including $4500 for the medical bill I got, few months later I got a check of $4500 from the hospital I was seen at...after contacting the hospital's billing department I learned that they were giving me back the money I paid for the medical bill because Medic Aid covered it So should I return this money to the insurance company