I have requested a withdrawal, but now I want to return the money to my bwin account.

Withdrawal cancellation depends on your location.
For customers in the UK, withdrawals cannot be cancelled once they have been requested, in line with regulatory requirements.
For customers in Ireland, you may be able to cancel your withdrawal yourself, depending on how far along it is in the process.

If this option is available, you will see it in your account. Once a withdrawal has progressed further, it may no longer be possible to cancel it.