APPROVED PREAUTH WITHDRAWN 6 MONTHS AFTER APPROVAL

The day I found out I was pregnant I requested a preauthorisation from Discovery for an elective C-Section. The procedure was Approved and a preauthorisation number for admission was provided... Since I recieved a sure okay from Discovery for this I thought all was in order.... 6 months later on the 29th December 22 I receive a devastating phonecall from one of their consultants informing me that they have "reviewed" my preauthorisation and have subsequently withrawn the preauthorisation with immediate effect! I asked the consultant why this was approved in the first place she couldnt give me a reason! Im highly dissapointed and i feel like i deserve a fair explanation for this! I couldve made alternative arrangements 6 months ago had i known that this procedure was not covered on my plan!..