Current Prime Members
You should recieve an email automatically from Amazon showing that your old Prime membership was cancelled and they are issuing a pro-rated refund. Obviously this is not guarenteed but it happened to me. The actual text from the email is below.
(from ahmadka: The second your new Prime membership is activated to get an email that your old prime is cancelled and that you would be receiving a refund within 2-3 days .. I got about $60 back ! )
"Hello from Amazon.com.
Your Amazon Prime membership has been canceled, per your request.
Since you received benefits on a small number of items, you will be issued a refund of $39.50 for the remaining months of your membership. If your membership charge has been completed, your refund should be processed within the next 2-3 business days and will appear as a credit on your next credit card billing statement.
You are welcome to come back any time and sign up for Prime again. Please know that we value your business, and we hope to see you again soon at Amazon.com.
To signup visit:
http://www.amazon.com/prime
Best regards,
Amazon.com Customer Service
http://www.amazon.com"