Hey! You can request refund at any time up until the keys are assigned to your account. Once the keys are assigned, you can either accept to reveal those keys and redeem at Uplay or request a full refund (which goes either to your Gamesplanet wallet or as a payout using the mean of payment). This is a fully automated process in your account, simply by clicking buttons. A detailed description can be found on the support pages.

The keys will be made available once preload has been greenlighted by Ubisoft. Preload date has not been confirmed yet but it likely will be end of next week.

Hope this helps!