Struggling to get authorisation

I have been struggling to get authorisation for a radiology procedure. Via email I was told that the claim will not be paid, via the call centre i was told that it will be paid as look as i get authorisation first. i have called the call centre at least 6 times, each time I need to provide them with something else. I have sent through a report and letter of motivation from the doctor, i have provided all the practice numbers, procedure codes, ICD 10 codes, all my details and still i cannot get a final answer about the procedure being covered. the response time over email is too long and the call centre waiting time is too long. I need the authorisation number by tomorrow. Ref BON***1