Claim not paid

I was referred to my ophthalmologist to visit a neurologist due to my severe headaches. I visited the neurologist rooms on the 11/08/2020 and had to pay cash for both my consultation and scans and was advised that since I had a reference number I could claim from you as this is a normal process. I sent through the copy of my invoice (with my referral number) to your claims email address and did not receive a response. I eventually received a response after my 3rd follow up which stated "claim cannot be paid due to no referral number". I highlighted my referral number and resent my documents however I have not received a response almost 2 months later. This is absolutely pathetic service!!!