Gems medical aid, poor service delivery. Very disappointing service

I am so dissatified with Gems Medical aid, I had a procedure and authorisation was approved, but the invoice is short paid, I have sent numerous emails queries and contact them directly, they are not willing to assist and not responding to my emails. Their agents are unprofessional and dismissive. I am so disappointed with their service. I have escalated the complaint to Medicalscheme for assistance. words cannot explain how frustrated and disappointed I am with Gems medical aid, they are quick to debit but not willing to assist with any outstanding invoices. My contact number is *** in case they view my complaint, which I doubt since they were not able to get back to me even after lodging numerous complaints.