Hello Brian1968,
Thanks for reaching out to the Apple Support Community. I know how important it is to maintain organization on your iOS devices to conserve space, and I'd like to help you stop those duplicate songs from re-appearing.
Probably the easiest way to resolve the issue is to sign out of your account under Settings > iTunes & App Store and then restart your device. Afterwards you can sign back in under the same settings.
As a heads up if you are an Apple Music member, you may need to re-download tracks for offline listening.
If you have any questions or concerns, the entire community is here to help.
Best regards