Getting Insurance companies to approve physical therapy for babies

My son's physical therapy was finally approved today after endless phone calls to the insurance company and to the physical therapy office. Documentation, phone calls, and faxes are all necessary to get your child the benefits that are rightfully theirs. Despite prescriptions from doctors, letters of medical necessity and endless documentation, my first insurance company continued to deny physical therapy benefits for my son. They kept saying "developmental delay" isn't a covered benefit. We tried again with "low muscle tone" and "generalized weakness", but without an actual diagnosis every effort was continuously denied. By some miracle, our insurance carrier was switched to a new one. This was initially a nightmare. I had just had my son's MRI approved by the pain in the ass insurance company, and a few days later, they were no longer our insurance company. I had to start all over again with calls to the doctor to start faxing all the required documentation to our new insurance company. The MRI was scheduled for weeks and the appointment was coming up in 6 days. I begged the new insurance company to expedite the approval for the MRI so we wouldn't have to cancel the appointment. I couldn't give up, I had to fight as hard as I could and call them every single day and stay on top of it for four days. It was horrible. Then I moved on to start keeping on them for the physical therapy approval. Next, will be the occupational therapy approval, followed by the speech therapy approval. I have yet to find out if the EEG will require approval.