Unfair

What should I do to get my money back. My son went in to see the dr at the casualty department of the hospital. I needed to make a co payment of R580 to the dr. I claim the money back from discovery and Discovery paid the dr. Now the dr have double payment. Discovery don't care for they did make a payment and me the client once again get nailed. Discovery said I must talk to the doctor and the doctor admin say I should talk to Discovery.