Could be targeted.
Unique promotion code can be found in email.
The start date in T&C should be an error.
Terms & Conditions
Throughout the promotional period, Prezzee will send customers who are opted in to receiving marketing emails a promotion code that allows them to get $5 off a Prezzee Smart eGift Card of $100 or more, which can be redeemed by entering the promotion code at checkout. This offer is valid for purchases of the consumer Prezzee Smart eGift Card of $100 or more on prezzee.com.au only. The promotion code can be used once per transaction. Consumer customers opted in to receive marketing emails from Prezzee can receive up to five promotional codes of $5 off a Prezzee Smart eGift Card of $100 or more on prezzee.com.au throughout the promotional period.
The offer starts on 4th November 2022 and ends on 28th February 31st May 2022. Prezzee reserves the right to remove this offer at any time without notice.
That is most likely to do with limiting number of transactions, not the code. Try another browser. It worked for me.