I purchased a ringtone but cant seem to get it to apply to a contact.

Hello Ms. Pie,

After reviewing your post, it sounds like you want to use a purchased ringtone for a specific contact. I would recommend that you read this article, it may be able to help the issue.

iTunes: Using the iTunes Store for iPhone, iPad, and iPod touch - Apple Support

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:

1. Tap the iTunes Store app.
2. Tap Tones. If Tones isn't visible, tap More > Tones.
3. Browse for tones. Once you purchase a tone, a dialog appears.
4. 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.
   
5. 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.

Thanks for using Apple Support Communities.
Have a nice day

Hey Ms. Pie,

If I understand correctly, you have a ringtone downloaded but not assigned to the contact. The steps below will help you to assign your contact a specific ringtone.

1. Select the contact you want to assign the ringtone to in the Contacts application or Contacts in the Phone app

2. Tap Edit and then select the Ringtone field

3. Select the ringtone from the list of ringtones that appears

4. Tap Done in the Ringtone selector, and then Done in the Contacts editor to save your changes

Thanks for using Apple Support Communities.
Have a good one