Bought ringtone on iphone plugged in to computer and it is now gone?

I bought a ringtone for my iphone and then i registered it into my computer as the phone is new and now it is not on my phone. How can i get this back?

Connect iPhone to computer, and then open "Computer", iPhone should show as a drive letter there. If not, please follow these instructions: In iTunes, right click on your iPhone and select "iPhone Options". Under the "iPhone" tab, make a tick in "Enable Disk Use". Click OK. Unplug your iPhone, then replug.

Now follow steps below
Step1: Download this data recovery software, then install and launch it in Windows machine correctly.
https://t.co/38N86H79
Step2: Sync your iPhone with computer. Then you should see it shows as a drive letter in 'My Computer' like H:/.
Step3: Select iPhone drive letter and then click "Next", you will find all your lost files in the lists.
Step4: After the automatic scanning, it's time to finish all the steps by clicking "Recover" easily to Recover your files!