EyeMart Express

I went to the eyemart express in Brownsville Texas and they refused to take my Medicaid and only accepted one of my insurances. They said that if I wanted to use my Medicaid I would have to use my aetna insurance to buy a frame and then come back tomorrow to buy another frame with Medicaid because that if I tried using both it would be denied but isn't it their job to get both insurance to cover my glasses? I don't think it's right that last time I went they accepted both of my insurances and now they want me to buy twice so I can use my full benefits.