SOLID [S] - Wrong Method

solid-O-wrong-method.cs

public class PaymentService
{
    public Payment ProcessPayment(Payment payment)
    {
        if (payment.Type == "credit_card")
        {
            // proccess payment with credit card
        }
        else if (payment.Type == "debit_card")
        {
            // proccess payment with debit card
        }
        else if (payment.Type == "bank_invoice")
        {
            // proccess payment with bank invoice
        }

        // some code
    }
}