Not paying refunds

I need help,with outsurance refund. I have a policy that was not supposed to be in place I. The first place. Meaning I am actually double insured, of which they did notice only after this year,from 2019. Now when they supposed to refund ,I am. It getting any response or communication from them as they promised.i always have to call and follow up. But I am not getting anywhere. Any advise in how to get this matter resolved