IFixIt it's an online shopping store, troubleshooting guide, and step by step phone or other devices repair. I recommend you to buy a screen that best fits your phone from Ifixit.com and follow step-by-step the replacement process. It's not that difficult I promise.
I recommend to restart your phone if you already haven't done so. If that doesn't help, call your voice mail and select "delete all messages" option. If the problem persists call your phone company as it might be a network error.