Discovery Health - always an excuse for not paying claims

I went for an MRI scan. My plan clearly states that the first part of the scan will be paid out of my medical savings and the rest Discovery will pay. Well, I got my statement back and they stipulated that the claim was rejected with a reason that there is a co-payment due for the full amount. When I phoned to query it, they then said that the claim was rejected because of a wrong ICD Code. How can an ICD code be wrong for a specific service? The company that performed the scan told me that Discovery covers the scan. They submit claims everyday to medical aid so how can they be blamed for Discovery rejecting a claim. The previous time I spoke to a manager (after two weeks of fighting with them) and she told me that the staff handling the claims have a predrafted list that they work with and if anything is not exactly as stipulated on the list then the claims are rejected. They claim to be the best medical aid but they can't provide their members with service or cover that they need/ stipulated in their plans. Discovery definitely have lost their personal touch and care for their members. I have been with them for over 20 years but the past 2/3 years have been a nightmare trying to get service, claims approved. It is absolutely shocking.