Please, contact us here, regarding this issue, as well please specify the following:
1. What is your Mac OS X/ Windows OS version? What iOS version is your iPhone running?
2. Did you use a song stored locally on your computer or searched for it online? If it's a local song - can you please attach it to your next reply, so we can test it on our site? If you searched for the song online, please let us know its exact name the way it looks in rising search results.
3. May we ask you to try exporting the ringtone to your local disk on the computer and let us know if you can locate it in the Downloads folder?