This scenario is the exact same thing that happened to me. When I tried to re-purchase the ringtone I got a message that said I already owned the ringtone and asked if I wanted to download it again when I replied yes it said that I was unable to complete the download. I tried both on my phone and my computer.
I contacted Apple support service and went through all the steps they emailed to me to get my ringtones back. None of them worked!
I ended up having to create a new Apple ID and re-purchased ringtones.
I also called and emailed to ask for a refund and was told that it is not possible to refund ringtone purchases as that they were already available to me to re-download.
I think Apple knew exactly what it was doing when they did this upload! Just another way for them to nickel and dime us to death.
Someone suggested that they were going to purchase a Samsung next time they have the opportunity to upgrade. I certainly am considering the same!