Yes u can but make sure you leave within the 30days so it doesnt turn to a deportation order so i was told by the immigration officer... you can withdraw ur application at any time if your suitation has changed in ur country and even if your refugee application was denied and you leave within the 30days specified for you to leave .. u can be allower back into canada but if you dont leave within that 30days and your deported then you can enter into canada again