bridge of contract and suspected *****

I thought I had the best Medical aid ever, until I was booked in the hospital for a procedure they approved only later to be told I'm liable for the rest of the payments. Now my question is when an Authorization letter is send to a member for approval why doesn't it contain an exact amount of what they will pay and why doesn't the best med app state that amount when all it say is " Hospitalization-Inpatient ,accommodation and theatre fees 100% scheme tariff pre authorization required "which was done and approved yet I'm held liable for theatre fees and equipment. what bothers me is that after receiving the news that I'm liable for payment I made a call to bestmed and the lady I spoke to told me that their fees were mentioned on the approval letter and I asked her to re send it to me but to my surprise the letter she claims she's resending looked totally different from the original approval letter that I received which now makes me see that they edited that letter to justify why they are not paying and to me that is *****. I was told on Chats with bestmed that the hospital did not send my clinical records hence the bill is not paid in full so I contacted the hospital and they send the clinical records plus a motivation letter but still the medical aid refused to settle all the outstanding amount. Now I need to understand how a member is liable for theater fees and the instruments used in theater when I was under general anesthesia was I the one using these equipment's on my self. why approve a procedure that you wont pay for and why isn't information provided to me via my app which contains my benefits and why isn't my app showing the remaining balance of this procedure and the amount I utilized like it does on other procedures like internal prosthesis under the "THIS YEARS REMAINING BENEFITS" I ask again, if lapscope, Adhesiolysis and Right tubal Cystectomy does not have its own field on my benefits it means it falls under the scheme inpatient hospitalization and theatre fees which the medical cover 100% following an approval which was granted. I think its time I started looking for other service providers the ***** and the stress is too much now.