Partsgeek.com Signed me up for a scam "coupon club" NJ

No problem with the parts or with customer service, but a few months after ordering I noticed a charge for $37.50 on my debit card to "RETAILDISCOUNTS 888-6983849 NY". They seem to be some kind of coupon club out of New York. I had never heard of them and had certainly never given them any money. I called their customer service and left a voicemail, then called my bank and reported it as fraud.

The next day Retail Discount Shop called me back and I told them I had already reported them as a scam. To my surprise, they sent me an email saying this:

"After placing your order with PartsGeek.com you were presented with an opportunity to join our club. We are a leading online rewards program that provides our members with exclusive discounts, rebates & price savings.  With over 250,000 local and regional retail merchants to choose from, you are sure to be able to find incredible price savings and discounts all across the country. You should’ve received email confirmation after the initial sign up confirming your membership. If you did not intend to sign up for this, we are sorry for any confusion you may have experienced.

We have cancelled your membership and issued a $37.50 refund.  Please allow 3-5 business days for the refund to reflect on your statement.

If there is anything else we can do for you please let us know."

I certainly never intended to give them money; after ordering from Parts Geek there was probably a window asking if I wanted some coupons, with a tiny box that I failed to uncheck. It was definitely not clear that this coupon club would cost me any money. Again, I have no problem with Partsgeek itself, but if they do business with such shady companies, I won't buy from them again.