Getting gas bills...harder than you'd think

I've been trying for a couple days now to make some progress on getting the gas bills (or at least the cost and use history) for this house. The problem is that I need 12-months, or better 2 or more years, of data to give us a good idea of how the house uses gas. I've only been here since August so only have a handful of gas bills.

I got the previous owner's signature on a release authorization form. Here's what I've done so far:
Jan 16
- I called Xcel Energy and they said due to a higher than expected call volume, they recommended calling another time.
- I looked in the phone book for a local office. Couldn't find any address other than Minneapolis (though I know there are offices in Denver.)
- Found a 'contact us' section of their website. Sent an inquiry asking for two years of history, and offered to fax the authorization. Received an immediate notice saying I'd hear back within three days
Jan 17 9 pm
- Got an email response from Xcel. Thanks for your inquiry. We'll initiate a request. We can only send you data for the time you were in the home. AAAARRRRRGGHHH! I already have that info.
Jan 18th
- I sent a reply to that e-mail restating (with some pomp and urgency) how the previous owner was happy to cooperate, how I'd paid for two energy audit programs, and how this info was needed urgently.