CaseServicesClient not rising exceptions when bad container ID is used

When using CaseServicesClient methods are used with non existent, malformed container ID, client ignores it and fails on not finding case instead.
Client should properly notify user that he has bad container ID and it shouldn't confuse user with message about case ID being bad.
In some cases there is no exception thrown, but it should be.

Also, error codes doesn't seem to match the error. For example when no stage is found, client shows error code 400, 500 and not 404.