I just located your post in the off topic folder and have moved it to the Install and Activate folder.
There is no phone purchase option. You can contact customer service (by email as a trial user -
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2) or you can activate OneCare with the key from a retail CD.
If you are unable to complete the purchase, verify that there are no characters in the data form other than letters and numbers. The form is very finicky about punctuation such as dashes, apostrophes, commas, etc. and doesn't present an error when your data contains them.
-steve