Why do you want to do this?

I've changed my mind about trading in my playbar.

I was going to upgrade to the arc but my TV doesn't supply earc. I didn't realise that you still get discount even if you don't trade in your old equipment.

So just going to get a sub for now.

I am not quite sure what you are asking, but if you have already redeemed an upgrade for your Playbar, you cannot revert that. Your best chance would be to call Sonos Support and ask if they can cancel the upgrade.

However, you can use the 15 % discount to buy a Sub, or you can save it for future use. You can still use your Playbar, even if it the discount has been redeemed.