Complaint about Discovery Health

My son was admitted at the hospital and Discovery Health paid money into wrong account, the money which belonged to Specialist and the doctor in question is planning to take matter legally against me. when i informed them that when i joined into the scheme i sent through my banking details to be changed they never changed them. and recently I sent through email to the CEO who then rep**** by saying i must go and speak to the person they deposited funds into to return the funds. Initially i told Discovery that i could not recovery the funds from the person whom the funds were deposited to. can someone help me since the specialist in question still has to see my son ongoing and how i am suppose to pay this money since its R15 000plus/minus and why must they not fix this since it was their fault, they have caused me sleepless nights and series of headaches with this issue. I'm in agony in need of help....