//Use the GetTransferReceiver method 
var client = new BFSServiceReference.bfsapiSoapClient();

var credentials = new BFSServiceReference.Credentials()
{
    UserName = bfsusername, //Username of administrative user in your instance of BFS
    Password = bfspassword, //Password of the administrative user in your instance of BFS
};

var persons = client.GetTransferReceivers(new BFSServiceReference.GetTransferReceiversRequest()
{
    Credentials = credentials,

    identify = bfsidentifier, //Identifier is a unique token for your instance of BFS  

    Args = new BFSServiceReference.GetTransferReceiversArgs()
    {
        TransferReceiverTypeKeys = new []
        {
			"DomesticBank"
        }

    },

    Fields = new BFSServiceReference.GetTransferReceiverFields()
    {
        BrickId = true,
        AccountNo = true,
        BIC = true,
        BankName = true,
        IBAN = true
    },
});

foreach (var c in persons.Result)
{
    Console.WriteLine(c.BrickId + "," + c.AccountNo + "," + c.BIC + "," + c.BankName + "," + c.IBAN);
}