Discovery medical insurance not paying for international traveling as stated in their documents

I want to report bad service regarding payment for international traveling to Australia for my Mother in April this year. We had to admit her to a emergency hospital for severe pain in her back and groin. We had to put down a deposit of 945.00 dollars. She was then admitted. Discovery was informed after she was released. Her ticket back to South Africa was changed from December to July to come and see her doctor. She was then admitted in South Africa for treatment. The outstanding balances in Australia after submitting all the relevant documents is still not paid. Payment demands in Australia is very serious and will red flag your credit record. Loose all credibility for no reason at all. Discovery is stalling payment and find excuses demanding more and more document that we do not have. Debt is now accumulating in Australia.