Coverage Exclusions not excluding private lines of code to be analyzed

We are almost hitting our plan, and want to exclude few folders to be analyzed to reduce private lines of code to be analyzed.
We have added those folders under administration > General Settings > Analysis Scope > Coverage Exclusions
But lines of code for the billing is not reduced. Am I missing something?

You will want to use Source File Exclusions, rather than Coverage Exclusions (which only excludes files from the calculation of code coverage). Keep in mind the documentation on Analysis Scope.