Sorry to see that you were having problems. What you described was a technical problem which has been fixed. Now you can use your password to activate the plugin and it will work.
If you requested a refund of your $0,99 then it's done, but your password will not allow you to upgrade the plugin anymore.
Why is it $0,99/mo not a one-off payment?
Unlike downloadable software for which you can pay once and use it forever, this is a web service. It requires a running server which is delivering contents i.e. fonts, and provide services i.e. "upload" tab where you can upload your fonts which are then converted using the service).
I hope that my answer was helpful and you'll be able to use the plugin without any problems.