iPhone 4S ringtone problems

I have ringtones downloaded that are purchased from Itunes and ones from from my Itunes library that won't show up to be used as ringtones. I have synched from Icloud and Itunes. They show up in the downloaded, purchased section in my phone but I can't select them as ringtones. I have a ringtone app also and this doesn't help either. I have tried multiple things. This was automatically done when I had the iPhone 4. Can anyone help? Thanks.