This company uses a very common practice of sneaking their ads into an an online merchant website, and hacking your credit/debit account, while you conduct your merchant business. Which is exactly what happened to me.
I made an online purchase, back on March 2008, with a well-known sheet music company, for an amount of less than $20. Upon closing my purchase no sight or seen was mentioned about any 'trial' Shopper Rewards membership, otherwise I would have immediately refused such, since I don't use them. And I always carefully check my bank activity twice a month, so there are no problems whatsoever.
Suddenly, ten months later, recently, I discover two separate transactions posted to my account, under this company--but same address--and contacted them immediately. The woman told me it would take 7-10 business days for a refund and explained about sending them a WRITTEN notice of cancellation, including a copy of my banking or overdraft statement. I told her I was more than happy to oblige.
PLEASE... be very cautious when conducting even innocent looking merchant transactions online these days! Even PayPal has been noted for error banking transaction activity, and they are the largest online payment system, connected with Ebay. Watch out for those teeny, tiny solicit ads on any merchant website. They are sneaky, and some websites will inadvertently collect your Debit information for these ripoff purposes. At least with a Credit card, your bank can refund the activity right away. It's tougher with a Debit transaction.
Protect yourself!