Declining authorisation even with motivational letters

Highly disappointed. I have a son who needs his tonsils removed. Just over a month ago we had to have him hospitalised he had a fever that I couldn't break we first went to see his pidiatrician and she told us to get him admitted. After 6 hours of trying to get a hold of the authorisation department they had the nerve to ask me why did I take my son to the doctor and told the lady from reception to keep an eye on us and to investigate while we're in the hospital. Getting back to the tonsils my son has had tonsillitis for the past 3 weeks he's had 3 different antibiotics in this 3 weeks the doctor, pidoatrician and specialist said we have to remove his tonsils. Medihelp has declined authorisation after 2 motivational letters from the specialist and put me under investigation again. My son's not eating or drinking, he's not sleeping which the specialist told Medihelp and still authorisation is being declined.