SOLID [S] - Extracting Method (Method with SRP) but with wrong class structure

solid-S-extracting-method.cs

public class PaymentService
{
    // ctors
    // properties
    // etc

    public Payment ProcessPayment(Payment payment)
    {
        var transaction = this.BankService.CreateTransaction(payment);

        payment.AddBankTransaction(transaction);

        this.NotifyPayment(payment)

        this.SavePayment(payment);

        return payment;
    }

    public void NotifyPayment(Payment payment) 
    { 
        var mail = new MailMessage();
        mail.From = new MailAddress(payment.Merchant.Email);
        mail.To.Add(payment.Customer.Email);
        mail.Subject = "Bla bla bla";
        mail.Body = "bla bla bla";
        SmtpClient smtp = new SmtpClient("smtp.gmail.com");
        smtp.Send(mail);
        // code code code
    }

    public void SavePayment(Payment payment) 
    { 
        using (var sqlConnection = new SqlConnection(this.DatabaseConfiguration.ConnectionString))
        {
            var query = "INSERT INTO Payments (...)";
            var result = sqlConnection.ExecuteReader(query, payment);
            // code code code
        }
    }
}