Tell Paypal what happened and they might be able to get you your money back.
I generally don't buy stuff like that on the internet; lectures at the local universities are totally free. You only really have to pay if you want to be marked for that stuff and take an exam as a registered student. A lot of universities are like that, actually.
Also, welcome to the forum!
Conlangs: Elysiani, Melkovin, Solmeia, Sorone, Tartaran
Current Projects: Multiple conlangs & conscripts, Voynich Manuscript translation