Reward Cancellation - Taxes?

Could anyone please help me with a query.

I'm looking to book a reward flight, so paying 'just' the taxes etc.
If I then had to cancel the flight, would I get a refund of these charges?

I've found the bit on the VS website which says that, outside 7 days, they'd charge 30 cancellation and refund 75% of the miles. But does this mean that I'd get a refund of all that I'd paid, less 30?

I believe if you don't fly, you can request a refund of the taxes regardless of the ticket cost on airlines where the tax element is shown separately.