Discovery worst Medical aid

I am honestly so sick and tired of Discovery Medical aid, I have been telling them since January that my email address is wrong and that I am not recieving emails from them, my son had to get his tonsils and adenoid removed and I called in to find out which ENT specialist is covered by them, they referred me to this Dr, and now I get this lovely bill for the anaesthetic doctor of over 4k, I call them to ask them what is going on they say the Doctor is only covered up to 100%, I say to them no one ever told me to confirm this, they ask me if I got the authorization letter stating all of this, I said to them no I didn't because I have been telling you guys my email address is incorrect, the advisor helping me says well this is our rules and it is not covered, I ask her to speak to a manager they have me for over 10min if not longer, The manager helping me is rude and unprofessional and speaking over an already upset client, I am so sick of Discovery taking advantage of their clients, they are **** expensive and then still pull **** like this, now they want to try and make this my fault and problem when if I said yes I got the preauth letter they would have said the letter states it, now that I am saying I didn't get it now they want to tell me bull**** about plan types and whatever else, I am taking this now to facebook, instagram and twitter as well, this call took now with the rude manager took place about 20min ago