Silly question but to take advantage of the Optus prepaid SIM cashback, I had to port my Coles number across 1 month earlier.
Technically that account still has available data and voice to use up for at least another month (annual Coles recharge is at the end of January)
Now that I have ported my number across, is there any way I can still access the remaining credit?
Nope. You port out of a provider, that effectively ends any benefit you had with them.