Hi Karen and so sorry for the trouble here with Facebook Events!
A white screen often means that there is a conflict with another plugin or the theme itself. I would suggest following the steps outlined in this article. If that does not work, then I would be happy to walk through these troubleshooting steps with you to see if we can pinpoint the issue.
However, if you’d prefer to refund instead, I totally understand and would be happy to process that for you.
Let me know how you would like to proceed and we can take it from there!
Thanks,
Geoff