Hey Friends,
I am Master Ramy, part of the Support Team for Jrummy Apps Inc, the company behind Rom Toolbox Pro and Font Installer.
What font did you attempt to install? Did the issue continue when you followed the aforementioned response from us?
Before attempting any customization, we recommend that users have a recent nandroid backup in case anything goes wrong. There are always ways to fix these issues, there should be no need to return your device.
Finally, I strongly encourage you to contact us with any questions or when you run into any problems, so that we can help you out
Feel free to post our responses to the XDA community if needed.
Thanks!
~ Master Ramy
Jrummy Apps Support Team.