Thanks for getting back with us, ant3708. If none of the steps we've taken thus far have resolved the issue, then a restore is definitely the next step to take. If you back up your iPhone as it is now, you will likely be bringing over the same ringtone issue to the iPhone after the restoration. You can certainly try though and see if just restoring from a backup takes care of those rogue ringtones. If not, you'll need to restore the iPhone and set it up as a new device, which means you won't be able to keep your content on there currently.
There are a few things to do first. Make sure to back up your iPhone before we try this step, by following this article: How to back up your iPhone, iPad, and iPod touch.
Once that is complete, you can try a restore from backup: Restore your iPhone, iPad, or iPod touch from a backup. If that resolves the issue, awesome!
If it does not resolve the issue, you will need to restore your iPhone again. This time, set it up as a new device: Restore your iPhone, iPad, or iPod to factory settings.
Since you are concerned about your photos and Contacts, we advise saving those separately. This link explains how to save those photos to a computer: Transfer photos and videos from your iPhone, iPad, or iPod touch. Additionally, you can download your Contacts from iCloud.com before the restore, then import them back on your iPhone later.
If you need further help during these processes, please reach out to us. Have a fabulous day and good luck!