wrong statement over a year

I was giving birth to the twins babies and they did not correct the names and depended codes of the babies on the bill statement ,i went and inform them that they must fix it they advise me to call the call centre on *** and i did so from August 2014 till to date as the medical aid informed me that the bill will not be settle until the information of the babies is correct .Every month i keep on checking if its updated but not at all till to date they even handed me on debt collection/attorneys because of them not doing their work . I will never ever pay that money because of their staff not doing job well.