Unpaid claim after receiving authorization

My name is Gary Wilder membership number ***. My Wife Doreen Wilder was in the Donald Gordon Medical Centre from 8th December 2021 to 16th December 2021. The hospital received a confirmation number NEO ***A from the medical aid but they have short paid R14261.80 of the bill. I cannot get hold of anyone there and when I send E Mails I just receive an automated response but receive no follow up. It is a real problem to query anything as they just don't answer calls and when they do they shift you from one department to the next until you are cut off after waiting for up to 30 minutes.