I tried to up date my Draftsight professional software from the help menu but Draftsight website downloaded an upgrade by mistake. I didn't realize this until I was asked for the new serial #. I need my DSPro back I can't see how to do it. Help?

How can I get my DS Professional back working on my computer when the DS Premium installed by mistake replaced my Professional subscription software?  Now when I start the DS Premium it wants me to activate it, but I want the DS professional program only to work with, not the DS Premium.  How would I do this and who can I talk to?