Please, take into consideration that according to the Customer Agreement: a client can withdraw funds from his/her account only to those payment systems which have been used for the deposit.
In case you made a withdrawal request via the payment system that differs from the payment system you used for deposit, your withdrawal will be rejected.
Also, please, kindly be reminded that you can monitor the status of your financial requests in the Transaction History. There you can see the reason for rejection as well.
Kindly note that if you have open orders while making a withdrawal request, your request will be automatically rejected with the comment "Insufficient funds".