Thought I would share my little loop hole / trick I found out..
Even though the Coles website says you can't use a Coles gift Voucher/card to buy other gift cards, however I just purchased a Visa cash card with my Coles vouchers, so essentially now allowing me to use that card anywhere Visa is accepted.
For example Coles charges I think a $6 activation fee, so $100 Visa cash card, for $100 Coles vouchers for a $6 fee
Here's a link to the copy of my receipt for proof it works š (I went through a register not self checkout, not sure if that makes a difference)
**Not sure if it works at Woolie's doing this
Then you can use the Visa card to buy groceries from Coles!