Успешный API POST не возвращает тело в ответе C#

Я выполняю исследовательскую задачу по интеграции стороннего API Authorize.Net. Я написал небольшое консольное приложение, нажал на API и успешно получил сообщение 200. Странно то, что ответ отображается в переменной метода, все, что мне нужно, есть, но на Swagger/Postman я не получаю обратно тело ответа. Мне это на самом деле не нужно, ответ есть в методе, и я могу сохранить нужные мне данные, но я считаю, что как Dev мы всегда должны учиться, и это поставило меня в тупик.

[HttpPost("ChargeCreditCard")]
public async Task < ActionResult > ChargeCreditCard(ChargeCreditCard data) 
{
    var result = await CreditCardService.Run(data);
    return Ok(result);
}

public class CreditCardService {

    public async static Task < ANetApiResponse > Run(ChargeCreditCard data) {

        ApiOperationBase < ANetApiRequest, ANetApiResponse > .RunEnvironment = AuthorizeNet.Environment.SANDBOX;

        // define the merchant information (authentication / transaction id)
        ApiOperationBase < ANetApiRequest, ANetApiResponse > .MerchantAuthentication = new merchantAuthenticationType() {
            name = data.ApiLoginID,
                ItemElementName = ItemChoiceType.transactionKey,
                Item = data.ApiTransactionKey,
        };

        var creditCard = new creditCardType {
            cardNumber = "4111111111111111",
                expirationDate = "1028",
                cardCode = "123"
        };

        var billingAddress = new customerAddressType {
            firstName = "John",
                lastName = "Doe",
                address = "123 My St",
                city = "OurTown",
                zip = "98004"
        };

        //standard api call to retrieve response
        var paymentType = new paymentType {
            Item = creditCard
        };

        // Add line Items
        var lineItems = new lineItemType[2];
        lineItems[0] = new lineItemType {
            itemId = "1", name = "t-shirt", quantity = 2, unitPrice = new Decimal(15.00)
        };
        lineItems[1] = new lineItemType {
            itemId = "2", name = "snowboard", quantity = 1, unitPrice = new Decimal(450.00)
        };

        var transactionRequest = new transactionRequestType {
            transactionType = transactionTypeEnum.authCaptureTransaction.ToString(), // charge the card

                amount = data.Amount,
                payment = paymentType,
                billTo = billingAddress,
                lineItems = lineItems
        };

        var request = new createTransactionRequest {
            transactionRequest = transactionRequest
        };

        // instantiate the controller that will call the service
        var controller = new createTransactionController(request);
        controller.Execute();

        // get the response from the service (errors contained if any)
        var response = controller.GetApiResponse();

        // validate response
        if (response != null) {
            if (response.messages.resultCode == messageTypeEnum.Ok) {
                if (response.transactionResponse.messages != null) {
                    Console.WriteLine("Successfully created transaction with Transaction ID: " + response.transactionResponse.transId);
                    Console.WriteLine("Response Code: " + response.transactionResponse.responseCode);
                    Console.WriteLine("Message Code: " + response.transactionResponse.messages[0].code);
                    Console.WriteLine("Description: " + response.transactionResponse.messages[0].description);
                    Console.WriteLine("Success, Auth Code : " + response.transactionResponse.authCode);
                } else {
                    Console.WriteLine("Failed Transaction.");
                    if (response.transactionResponse.errors != null) {
                        Console.WriteLine("Error Code: " + response.transactionResponse.errors[0].errorCode);
                        Console.WriteLine("Error message: " + response.transactionResponse.errors[0].errorText);
                    }
                }
            } else {
                Console.WriteLine("Failed Transaction.");
                if (response.transactionResponse != null &&
                    response.transactionResponse.errors != null) {
                    Console.WriteLine("Error Code: " +
                        response.transactionResponse.errors[0].errorCode);
                    Console.WriteLine("Error message: " +
                        response.transactionResponse.errors[0].errorText);
                } else {
                    Console.WriteLine("Error Code: " +
                        response.messages.message[0].code);
                    Console.WriteLine("Error message: " +
                        response.messages.message[0].text);
                }
            }
        } else {
            Console.WriteLine("Null Response.");
        }

        return response;

    }

}

Тело ответа в методе:

message [messagesTypeMessage[]]:
{AuthorizeNet.Api.Contracts.V1.messagesTypeMessage[1]}
[0]:
{AuthorizeNet.Api.Contracts.V1.messagesTypeMessage}
code [string]:
"I00001"
text [string]:
"Successful."
Non-Public members
resultCode [messageTypeEnum]:
Ok
Non-Public members
profileResponse [createProfileResponse]:
null
refId [string]:
null
sessionToken [string]:
null
transactionResponse:
{AuthorizeNet.Api.Contracts.V1.transactionResponse}
accountNumber [string]:
"XXXX1111"
accountType [string]:
"Visa"
authCode [string]:
"HTBIYF"
avsResultCode [string]:
"Y"

Ответ возвращается в Swagger