Smart, or not so smart?

Discovery, I have been a client of yours for close to five years now. About 2 years ago, I switched to the Classic Smart plan. I have had hardly any issues, bar a recent event. In December, I went to my normal practice, which is listed on your app under find your provider as a fully covered network provider. Please note that the PRACTICE is listed. I come out from the consultation to be told that you will not cover me. I pay, the medical aid rate mind you, and submit the claim to you thereafter. You then refuse to pay my claim?! The reason you gave as to why you will not cover me is that the doctor I saw is not listed as part of the network. How is this acceptable, when A) the PRACTICE is covered, and B) the doctor I saw runs half of this practice! I have been getting absolutely nowhere with your consultants, despite providing them proof that the PRACTICE is covered, and that this doctor runs half of said practice. This is really poor show on your part. This is MY money and I have abided by your rules. This exact question was in fact brought up in our company presentation by myself at the end of last year, and I was told that as long as the HOSPITAL or PRACTICE is listed on the network, and I abide by those rules, I will be covered? Please tell me why the practice is listed as fully covered on the Smart network when you are in fact not willing to cover?