Tax Invoice

I took my son for a rapid test. To my surprise unlike what they allude to on their website I had to pay in cash. I am now liable to go through a vigorous process to claim back from my medical aid. I have sent the test results to Dis-Chem and is still waiting for the tax invoice in order to claim back from my medical aid. I need the tax-invoice by latest 26 August. My reference is VIS***.