Refactor for using ChannelFactory
I don't know any Spanish so it was a bit difficult to understand exactly what was going on (I recommend you provide English translations/descriptions of non-English class names and string literals as comments next time).


Why do you create a temporary variable that is only use to set another variable on the very next line instead of just setting it directly? (iDependencias &amp; depClient).
You close the channel if it's a DependenciasClient but don't clear the reference to it. svcDependencias is visible outside this method and having it hold a reference to a closed connection may be a problem.
You don't check to see if svcDependencias is already set before setting it to a new connection. I don't know if you can re-use the connection, but you should at least close the existing connection before you loose the reference to it.
I noticed that you only close the channel factory if the channel is not a DependanciasClient. While this will probably work ok if the channel factory never returns a DependanciasClient, I think a null check would be a clearer solution.

if(customChanelFactory != null)
{
    customChanelFactory.Close();
}

Instead of using the 'is' operator followed by a cast, you should use the 'as' operator and check for null.

DependenciasClient client = svcDependencias as DependenciasClient;

if (client != null)
{
    client.Close();
}

If svcDependencias only exists at the class level for the benefit of GenerarDependenciasDeFormulariosFmb then personally I would prefer to pass it in as an argument rather then use a class field.