Anadolu Sigorta Supplementary Health Policy Exclusion of Pre-Existing Breast Tumor

I have experienced an issue with my Anadolu Sigorta Supplementary Health Insurance Policy No. 1335505821 during the 4th renewal regarding excluded illnesses. In each of my policies, a biopsy was requested for a routine examination, and after the biopsy report, a breast tumor diagnosis was made.
During the process (3 years), all examinations and expenses were approved by the supplementary health insurance (TSS), and after the performed biopsy, a tumor diagnosis was made. Until the end of the policy, all our tests and examinations were covered. When our 3rd policy expired, we renewed it. During the renewal, we were not informed about any excluded illnesses. A few days after the renewal, we were notified that the breast disease for which a tumor diagnosis was made and all related examinations and other expenses would be excluded from coverage. The reason given was that a cyst diagnosis was made in the breast during an examination conducted before the insured process.

If this is the reason for exclusion, why were all examinations and checks covered until now?
Are cyst and tumor the same thing?
Is it normal for all examinations and expenses related to a diagnosed tumor to be covered in the policy and then not included in the next renewal policy?
If the insurance made a mistake, if they should not have covered it, why did they cover the examinations and expenses after the biopsy was performed?
Is it legal for the insurance to make a mistake, not exclude the illness in question in the renewed policy, and then, a few days after cutting the policy, inform us by SMS that it is excluded?

This is a contradictory, sad, and very wrong situation. I want it to be corrected, and if not, I will write to all relevant places, including CİMER, and it should be known that I will never work with Anadolu Sigorta again after my current policies expire. I demand that the excluded illness added to our 4th Renewal policy be removed and included in the policy to resolve our grievance and maintain customer satisfaction.