Unfortunately, many physiotherapy clinics have too close a relationship with the insurance industry. Remember, your insurance company does not have your best interests at heart (they will look after their own economic interests first – which means avoiding paying out funds if at all possible). If they discover a way to avoid paying for treatment, they will. Insurance companies will recommend particular physiotherapy clinics on the basis that those clinics will complete treatment and discharge you as soon as possible.
It is important to tell your physiotherapist that they do not have your authority to communicate with your insurance company. Pay for treatments yourself and keep the receipts. If you can afford to do so, wait until you have finished treatment and then send the receipts in to your insurance company for reimbursement.