You will not get a phone number here as phone support is only available for validated subscribers and anyone can read the forum. See this post for how to reach support:
How to reach support (FAQ) - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=2421771&SiteID=2
In any event, you are not explaining what the problem is when you attempt to renew.
To renew your subscription:
Open OneCare, click on Help/About... Note the subscription ID shown
Open your browser and sign in at http://billing.microsoft.com with the LiveID shown as the subscription ID in OneCare.
Select the OneCare subscription shown.
Click "renew this service."
You should see a page with the following (as of 2/26/08 verified with a US paid account):
Plan Description
To renew your subscription with a Product Key or prepaid PIN, click here.
To renew your subscription with a credit card, direct debit, or other payment method, click Next.
Select the option you prefer and provide the requested information. Note that renewal takes effect on the date that your current subscription expires and that it may take up to 24 hours to reflect the updated subscription status in OneCare.
-steve
