Discovery poor service

Discovery is refusing to pay a claim submitted in March, despite receiving all the documentation they requested. When I follow up with them, their consultants put you on hold for a very long time as if they want you to end up dropping the call. They would then tell me that the claim hasn't even been processed. I've sent a complaint but they did not respond. I am exhausted with Discovery poor service, I had to pay this claim myself and they won't reimburse me.