How to delete a custom-made ringtone from an iPhone 4?

I made a ringtone and I synced it to my phone and then I didn't like it so I deleted it off my computer and iTunes. Then I made a different one and I liked it so I kept it but then I noticed that there were two of the same ones- the new one i made and liked and the old one that i deleted. The file isn't on my computer anymore or my itunes and i don't know how to get rid of it.
I've tried restarting my phone and resetting it and it's still there, and i don't want to reboot it cause i have a lot of stuff i can't back up and i wanna keep on my phone so how can i delete that extra ringtone that i already deleted off my computer?

First of all, is your iPhone jailbroken?
If so, you can download iFile from Cydia, then you go to:

/ var / mobile / Media / iTunes_Control / Ringtones

then you check which one among the existed ringtones is your old version, and then delete it.

If your device is not jailbroken, then try to download iTools from the link below:
http://itools.hk/tscms/public/uploads/iTools0913E.zip
then you go to "Media" under your iPhone's name and then from the right panel select "Ringtones" then you can check whether the old version is exist or not, and for sure if it was there, simply delete it.