Oneplan Health Insurance
Why do I have to pay

I was in a car accident on the 4th of Jan 2013. My husband took me to the hospital and they wanted to do a CT scan. We phoned One Plan and they said I had to be admitted to hospital before they would cover it. So the hospital admitted me and then did the CT scan. Now one plan sent me an email stating they cant cover the CT scan and I have to pay the bill of over 12000 rand myself. Why am I paying them for cover if they cant cover my bills