Using WF to make call to Soap Service over HTTPS - wcf

Question

I've tested the endpoint against Postman, it does exist despite what visual studio is claiming. There's errors in the app.config file when I add the service reference so I decided to configure the binding and endpoint manually in code.
Script task:
public void Main()
{
//configure WCF manually , endpoint, HTTPS binding, etc
BasicHttpsBinding binding = new System.ServiceModel.BasicHttpsBinding(BasicHttpsSecurityMode.Transport);
EndpointAddress address = new EndpointAddress("https://service/services/Operation.svc");
ST_364d1c14d92b406e87f51c75a462f403.ClientServiceRef.ClientService1Client client = new ClientService1Client(binding, address);
client.ClientCredentials.UserName.UserName = "";
client.ClientCredentials.UserName.Password = "";
//make call to SOAP service using client instance
var column_names = client.GetAllClients();
Dts.TaskResult = (int)ScriptResults.Success;
}
Runtime error - doesn't seem to recognize endpoint
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
at Microsoft.SqlServer.Dts.Tasks.ScriptTask.VSTATaskScriptingEngine.ExecuteScript()
For reference here's the app.config file
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpBinding_IClientService1">
<security mode="Transport" />
</binding>
<binding name="BasicHttpBinding_IClientService11" />
</basicHttpBinding>
</bindings>
<client>
<endpoint address="https:/server.com/services/ClientService1.svc/soap"
binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IClientService1"
contract="ClientServiceRef.IClientService1" name="BasicHttpBinding_IClientService1" />
</client>
</system.serviceModel>
</configuration>