@OP, you are not alone, I have this exact same issue.
It's been a week since my trial expired, and I've been selecting that "stay downgraded" option every day.
The box won't even disappear on its own, and persists on top of every other window.
I've had enough and finally uninstalled the program. This behaviour is as bad as the malware it's supposed to protect me from.
My first time visiting the help forums and I see posts like this from what looks like a staff member?
Someone comes to your site looking for simple help and you not only ignore the question, but attempt to coerce him into using scare tactics on his customers in order to get them to pay for your software?
Seriously? What a fine first impression.