refusing to pay claims (member number ***)

I went to see a dentist for my yearly cleaning in June and they ingwe health refused to pay the claim (doctor) because they say the doctor is not on their primary care network. I had to pay out of y own pocket. Now I want to go for another clean up and I am willing to go to a doctor on their primary care network and they are saying they will not pay the claim because I visited a dentist in June. In June I paid with my own money they did not pay for it. Why are they refusing to pay now yet in their contract they agreed to pay for one dental visit