There is an Open Account sample csharp file and it has the code below.
/// Sample code in this namespace uses C# and the SOAP 1.2 API endpoint.
/// A WCF service reference was created using https://uatapi2.vantiv.com:8031/v3/ApiService.svc?wsdl.
/// This sample shows how to sell a card using ValidateCardholderIdentity
/// and OpenAccount.
public class OpenAccountSample
Where can I download the dll Vantiv.Prepaid.Api from?
I downloaded sample code files from Vantiv Prepaid Api Guide.