I was also one of the online shoppers affected by reservationrewards.com.
When i realised that I was trapped and brought it to the attention of the company,
Mary O'Reilly of Consumer Affairs at Reservation Rewards was swift in her response and immediately resolved it for me. Highly responsive and I really appreciate that. See the reply from her below:

Ravi
Seyyone Technologies, India

Dear Ravi:

Thank you for contacting us so that we can accomodate your request. We located your membership record, cancelled it and processed a refund of the charge as you requested. This refund should appear shortly as a credit in your account depending upon how frequently your credit card issuer posts transactions. You will not be billed again.

At this time, we'd like to provide you some information on how the membership was initiated. Our records show that on October 1, 2008, when you completed an online transaction at www.buy.com you enrolled in Reservation Rewards by clicking on a $10 cash back award, entering your email address twice and clicking the “YES” button on the enrollment form. Directly above the section for entering email addresses, the text advised you that you were authorizing the secure transfer of your name, address and credit or debit card information to Reservation Rewards for billing and benefit processing. Immediately after accepting the membership offer you were presented with a membership acknowledgement page and within 10 minutes a membership confirmation email with details on how to use the membership was sent to your email address. We'll send you copies of these pages for your review in a separate email. We sent six more emails to your email address from October 1 through October 31, 2008 with details of the membership. The one that was sent to you on October 19, 2008 informed you that your 30-day free trial would end in 14 days and that you would be billed unless you cancelled your membership. If you would like us to send you copies of these emails, please let me know.

Even though your membership is cancelled you can still redeem your $10 cash back award on your next Buy.com purchase with no further obligation to Reservation Rewards. Simply use your assigned PIN code, W87HC582, when you make your next Buy.com purchase.

We hope this resolves this matter to your satisfaction and demonstrates that proper authorization was obtained to charge your credit card. If you have further questions regarding this matter or suggestions for improving our service, please contact us at [email protected]..

Regards,
Mary O'Reilly
Webloyalty.com Consumer Affairs
Reservation Rewards