How to restore ringtones purchased from iTunes

I had an iPhone 4 and I've bought some ringtones from iTunes store. They were working good until I got an iPhone 5. I got absolutely everything restored to it except my ringtones. I literally looked everywhere, but I couldn't find them. I bought only one ringtone this time. Now I changed my phone again and once again I lost the ringtone. I can't find it anywhere. It's not it in my purchased items in iTunes, it has just vanished. Is there any way to restore it? I just find it really unfair. I can restore all my music, but I have to buy ringtones all over again?! If that's the case I'll just not buy from iTunes again.

I've googled it, but couldn't find a working solution. One said to uncheck the ringones when you sync your iTunes. I can't even find a place to check or uncheck ringtones on the newest iTunes. I think it was maybe for some older version. And here on the discussion boards someone told that I can email apple with my order number. But they also said they'll send them to me only once. So what happens if I change my phone again? And I'm intending to do that, I'm not going to use that phone forever and I don't want to lose ringtones every time.