Mechanix & Scene are Expansions for Massive X.
Not for Maschine!
If you don't have Massive X, then they are totally useless to you.
If you ask politely some of the admins here, they might be able to exchange your purchase.
However since it was an online purchase and you have already downloaded the files, officially there is no refund. If they exchange them, it will be out of their good will.
Your other solution is to try to sell/exchange them, here:
Which expansion packs did you recently install? Some of them are loops/one-shots or even presets for Massive.
Do you have Massive X or not?
It's an application, a synthesizer actually, not "files".
