^^^this question has been asked, and asked, and asked.
Mac policy is that you can b2m any 6 glass, metal, or plastic empties and receive any lipstick (bullet, slimshine, mattene or prolongwear-excluding VG) at counters. At stores, if you have your personal info entered into their system, you can also choose any shadow (excluding pans) or any lipgloss (excluding VG). All of these items can be perm or LE. Stores now limit recycles to 24 empties at one time.
Again, this is company policy, however not all locations follow it. Call your local counter/store to check their policy.
I've included all details of the policy, so hopefully (but doubtful), this question will not be asked again.