As annoying as that would be if I hear such text tones, here's what you need to do. You require iTunes and a computer (Mac or PC) to load new ringtone or alert tone.
- Launch iTunes on your computer
- From the FILE menu, select “Add File To Library”
- Find and select the Ringtone (.m4r) file
- iTunes will then import that file into the iTunes Music Library
- After the import, the .m4r file will be located under the Ringtones section in the Music Library!
- Sync up your iPhone
- You should now be able to choose the ringtone/text tone for any of your contacts