Activation Request Code Help

I bought a new computer recently. And have a single user version of Mathcad 13 (legitimate copy bought through Newegg for $1200).

When I tried to install it on my computer, everything installs ok. However, when I attempt to open the program nothing happens. I've contacted support and they tell me that version 13 is no longer supported and that they are unable to send me a license file without the "Activation Request Code." Which I'm told is supposed to automatically appear when I attempt to open the program.

But, nothing happens! I'm at my wits end. If anyone can advise, I'd greatly appreciate it!

Thanks!