Unfair claim declined, what are we paying for??

I went to see the GP 21 Feb'19 very sick and test done and symptoms pointed to kidney stones and the doctor sent me to hospital on the same day i called Discovery to tell them that the GP advised that i must go to hospital due to further investigation of kidney stones. what must i have and even confirm if Medforum was the network hospital, and i did all of this to avoid non payments problems at the end. when i called i was not advised that should the scanner show no kidney stone there wont be a payment. now the hospital is calling me for payment. I contacted Discovery and they advise that the claim was declined due to some reports missing, i called the case manager at Medforum to submit and it was done, still no payment now the claim is declined because at the time of going to scanner the stone was not found, i feel the reason for decline is very unfair because i had a kidney stone before and when i got to the theater is was passed with the urine. so now i was supposed to be sure if the stone was there before i was admitted, how possible is that because i don't have a scanner at home and also my GP did have hence i was sent to hospital. another thing i am a high blood chronic patient my blood pressure was very high when i got to hospital because of pain, i couldn't walk because of the back pain my urine was full of blood and still i was suppose to be worried about hospital bills off which i must have peace of mind as my health is covered and paying premiums for almost 10 years to Discovery