Confused about coverage

My daughter received physical therapy due to torticollis , our insurance NYSHIP has a few different parts to it . The physical therapist office was sending the bills to the hospital side ( Blue Cross Blue Shield) they were denied because Blue Cross Blue Shield will only cover physical therapy after a surgery or hospitalization , they told me that they were aware of that and that they always send it there first and than to the united healthcare side of things . I just got EOB in the mail stating that the claims were denied With processing codes 73 ( saying to submit to blue cross blue shield) and ND stating that it is an out of network service and was paid based on a Medicare allowed amount , I see no where in the EOB where anything was paid and we used an in network hospital system . According to the UHC website physical therapy is covered under the managed physical medical program, is this where the office should be sending the bills ? I know for a fact that the hospital system we used is in network as all of our other medical care is through them , I am just so confused and don’t want to be on the hook for thousands of dollars.