Not refunding my money and *********** staff!!!

I sent through a claim for optical benefits in April 2015. I always pay my optometrist cash and claim back from Hosmed as my Optometrist does not work with them as they take too long to pay him out. I called the Hosmed call centre a month ago and was told that the claim was received and was being processed so I should call back in the 1st week of June. I called the optical benefits call centre yesterday and was told that they didn't even receive the claim from Hosmed! I then called the Hosmed call centre and was told that the claim was rejected as there were no codes on the invoice from the optometrist to process the claim. This is ******** as I always send through the invoice with proof of payment and there isn't a problem. I asked to speak to the supervisor (Moipone) but Virginia said she was not at her desk. I asked to leave a message for her to call me back urgently but Virginia refused. She then said she will forward the claim to the optical benefits department and call me back yesterday but didn't! I had a look at my invoice and there are ICD 10 codes on it! The service regarding the refunding of claims is pathetic and the call centre agents are not very helpful!!!