Can a rehab facility deny admission due to denied dos from a previous stay? Appears it is an error on the facility part.

My dad was in a rehab facility for 3 months earlier this year. He just recently had a massive heart attack, and when the hospital requested him to be admitted for rehab, he was denied due to dos being denied from Medicare on the previous stay. Can a rehab facility deny admission due to previous dos being denied because they were filed wrong?