Extremely poor service

Why is there no zero rating? What this medical aid is putting me through is really not fair. I visited Dischem clinic and I was given invoice to claim back from the medical aid. Instead they keep saying that the documents are either not clear or invalid practice number. I sent more than 3 emails and even requested them to give me adress so that I can either deliver or post them. Instead they dont want to refund me my money. They dont even get an agent to call instead they just send unjustified emails