Wind Simulator fans blowing wrong way!

this is my first post so please go easy!

I just took delivery of a ready made wind simulator. Everything is set up correctly in Arduino etc. But for some reason the fans are blowing in the opposite direction. I have even reversed them in their casings but still the same. 
I bought it on Ali express after reading good reviews. Have I bought a dud or am I missing something!?

would appreciate any advice!