Essential Med review: Non payment 1

Essential med will not pay my claim as they are adamant that the claim is for something completely different to the actual medial reason submitted which includes the doctors letter. I have asked them to read all the documentation and then confirm when the claim will be paid but they will not.
Worst customer service I have ever experienced in my life. They will not even follow up on communication sent and questions asked. I was told my claim has been sent for processing and 2 months later I am told the claim could not be sent for processing as they don’t have a doctors letter which I personally supplied 3 days after admission.