Hi, Finally found this group! Is here somebody who could help me?

I already purchaced a draftsight Standart version, but serial number code was not accepted! Well, I loaded another version, but seems to be IOS demoversion. It shows the watermark in the drawing that I try to print.

What to do? What is the right version for MAC. How can I get it? How can I get my money back if the version that I already purchased is wrong? Is there a Standart version for MAC available at all?

I really appericiate the help.