If you say when(cltMock.getSalesforceClientObject(client,mockMap,"yagyesh.mishra@intelligrape.com")) then the arguments you pass to the method must match by the equals method to what you are setting up in your when block. That means your Configuration class must have an equals method which returns true for the object you passed in the when clause and the object that is passed at runtime. The same with the SalesforceClient class.
Often you don't care about the exact instance passed to those arguments in pure unit tests (scope of test should be small anyway) so you will typically see others write this as
and
Note that the string parameter in this case needs to be wrapped in the eq function because mockito doesn't allow you to mix exact values and those defined using any.. in one method call.
Your code is not testable and you are not using Mockito properly.
If the method you are testing has
then you can't provide a mock SalesforceClient to it.
You either need to provide that to your method as a parameter or make it an instance variable then mock it and inject the mock using @InjectMocks or similar.
Also, what does your getConfigProps(cloudConfig) method do? In order for your mocked version to be called you again have to call it on an object that you are injecting as a mock.