pls help (urgently if you can) - when customer is created can't add credit card info

This is my code below (c#) - customer and address are successfully added, but credit card info is not added at all. What i'm doing wrong? The credit card add code is between the comments "credit card add code begins/ends"

protected void LinkButton1_Click(object sender, EventArgs e)
        {
            this.login();
           
            Customer customer = new Customer();
            customer.firstName = TextBox1.Text;
            customer.middleName = TextBox11.Text;
            customer.lastName = TextBox12.Text;
            customer.email = TextBox2.Text;
            customer.companyName = "test customer";
            customer.phone = TextBox3.Text;
           
            RecordRef status = new RecordRef();
            status.internalId = "13";
            customer.entityStatus = status;

            CustomerAddressbook address = new CustomerAddressbook();
            address.defaultShipping = true;
            address.defaultShippingSpecified = true;
            address.defaultBilling = true;