Medsheild withholding information

I have been struggling for over a month to get information from Medsheild regarding claims that had to be resubmitted as my hospital authorisation only came after many of the claims were submitted owing to it being an emergency and Medsheild then wanting to prove a pre-existing condition which it wasn't in October 2019. They, to date, have been unable to provide me with the repeatedly requested information regarding 4 claims. I have now escalated my query twice and I am still waiting for feedback. Their withholding of information to me suggests that they do not have a valid reason for underpaying my claims. I am now regretting moving to their medical aid scheme earlier this year.