First off, let me tell you unfortunately the SGH-A107 was rated a mediocre phone so you won't find a lot of the features you are looking for in a modern cell phone, such as an external display and the common bluetooth connectivity

. That being said, you won't find a feature to block or reject calls (messages, yes

) like you can on Android-based phones and iPhones. AT&T didn't invest a lot of money when it made this prepaid phone (probably not marketed with a lot of features either).
But! There is hope!

There are a couple of things you can do.
The first thing is if this is a brand new number and you haven't moved anything over or advertised your new number call AT&T right away and demand a new number. If they refuse threaten to make a complaint with the FCC. It is common for wireless providers to save money by moving over a number already on their network rather than registering it again.
Second, add your number to the FCC do not call registry. Usually the number registration is good for 5 years so it is possible if it is a used number that the time could have lapsed.
Third, add the number to block messages. Follow these steps:
1. Go to Main Menu
2. Go to Messaging
3. Messaging Settings
4. Select 1 for Text Messages (SMS) or 2 for Multimedia Messages
5. Select Block Number and enter it
6. Save your settings by pressing the left soft key.
7. If you change your mind go back to the selected number, go to options, and press delete.
I hope this helps!
Thanks, Jessica
Customer Loyalty Team