Are you trying to make the purchase from your phone or on a computer? Does it give a specific error message? All the network settings so far have looked ok. If you are doing this on your computer have you tried to clear your cache and browsing history, reboot and attempt again? Or try a different web browser all together? If from the phone, you can try to clear your history and cache as well (internet>menu>more>settings>clear cache,history,cookie).
I am trying to purchase a ringback tone name of the song is The Love We Had Stays On My Mind (Chorus) by The Dells. But everytime I click the Pruchase button it errors out. Can you help with this?