i got missed call from this number what when i tried to call on this number they didn't pick up

i think she is from some course on line agency

http://upskillonline.com.au/contact-usOffering some online course, no idea how they've got a hold of my number. I'm calling it spam

Number called me and hung up within 2 rings rang straight back and no answer.. Who is it..??

Got a call from this lady who asked if I received some text and I said no and then she said I should have and asked if I want to do some stupid course, no idea wtf the b***h called for but weird as

http://upskillonline.com.au/contact-us

Offering some online course, no idea how they've got a hold of my number. I'm calling it spam