Hi Muribe6801,
Welcome to the Support Communities!
The article below will explain where to find the ringtone you purchased on your iPhone and how to assign it to a Contact:
iTunes: Using the iTunes Store for iPhone, iPad, and iPod touch
http://support.apple.com/kb/ht1491
Tones
You can't purchase ringtones and alert tones from your computer, but you can purchase them using your iOS device with iOS 5 or later. You can purchase tones on iPad, iPhone (3GS or later), and iPod touch (4th generation or later).
To locate tones in iTunes on an iOS device:
- Tap the iTunes Store app.
- Tap Tones. If Tones isn't visible, tap More > Tones.
- Browse for tones. Once you purchase a tone, a dialog appears.
- Choose to set your new tone as your default ringtone or assign it to a contact. If you don't want to do anything with the tone, tap Done.
- Tones you purchase using your iOS device sync to your iTunes library when you connect your device to your computer. You can find tones on your device in Settings > Sounds. In the Sounds and Vibration Patterns section, tap on Ringtone. Then scroll to the top of the list to see your custom ringtones.
If you don't assign a ringtone at the time you purchase it, you can always add it to a contact later:
Set a special ringtone for a contact - Phone - iPhone Basics - Apple Support
http://support.apple.com/kb/TI16
In Contacts, choose a contact, tap Edit, then tap Ringtone. Select the ringtone you'd like to hear when that person calls.
Download past purchases
http://support.apple.com/kb/HT2519
If you made a backup of these items on your Mac or PC, you can sync the items to your iOS device. You can't download these items again from iTunes in the Cloud.
Cheers,
- Judy