TRS (Rejected) Tourist Refund Scheme : Tax invoice request

I recently bought a few items from Apple Highpoint, Apple Pty Ltd, Highpoint Shopping Centre, Maribyrnong Victoria 3032.

I live in India and travelled to Australia when I bought these items.

I wanted to get a TRS (Tourist Refund Scheme) claim as I am supposed to get back the VAT paid as I am not Australian.

When I went to the TRS office in Melbourne Airport they rejected the claim saying the email receipt you are showing is not a tax invoice and they will need the same.

I reason for rejection stated was "Not an original tax invoice".

How can I get the "Original tax invoice"?