Thanks for this information!
If you only have 20 events, then unfortunately this suggests other problems on your site. I cannot recreate any performance problems with that number of events.
I would recommend trying to deactivate ALL plugins on your site except for only The Events Calendar and Events Calendar Pro.
In this state, how do things behave?
If you do not want to do this testing, and would like a refund, then I totally understand—there is unfortunately little we can do about performance issues like this, because if things are running slowly with only 20 events then there are server issues or other code-related issues on your site. 🙁 You can get a refund by following the steps here.
Sorry for the trouble!
George