Thank you Roger for the post. Worked perfectly. I setup a call back and the apple tech called me within a few minutes. After about 5 minutes on the phone he processed my refund. Note that I manually downgraded my plan through my phone to the lower cost one prior to calling the tech guy, but obviously that is not enough to immediately process the refund (unfortunately). Anyway he said for the current month I would still have the higher storage plan, but the refund would be processed and I would be stepped down to the lower plan at the end of the month cycle. Thanks
What Roger said that worked for me:
You may be able to do this using http://expresslane.apple.com - Click on 'More products and services', then 'iCloud', 'Account and setup' then 'This topic is not listed'. Explain the situation in the box provided and wait for a response - include a phone number. However you may find you cannot proceed without entering a hardware serial number which is still eligible for AppleCare.
In that event you will need to phone them directly, using the Apple Online Store number given at the bottom of this page. The first person you speak to may tell you to do it from the iCloud website but this is not possible. Politely insist on escalating the issue to a more senior person and eventually you should be able to get through to someone who can deal with this (you may have to wait for them to call you back) - you will be asked security questions and for part of your credit card number to identify yourself.
If it is more than 15 days since you purchased the storage you cannot cancel it for a refund; you can downgrade your plan as from your next renewal date. Please see
http://help.apple.com/icloud/#mmd602084a
and expand 'Downgrade your storage for the next plan year'.