STOP WORRYING. A lot of small businesses use "Square Reader" service to process your credit/debit card transactions. I use it at craft fairs... Did you have to "finger sign" on a tablet to complete the purchase? If so, it was Square they swiped you through, and you got the email survey because your bank the card is drawn on has your email encrypted into it. Not uncommon at all. If you don't want to do the survey, just don't do it. Square isn't going to rip you off. They rely on secure transactions to stay alive, as a business. Just like Paypal. Relax.
Square is a really cool little service for people who do transactions once in a while, and I've even seen small stores using it. They provide a free card reader and for a small percentage will transfer the funds directly into you acct.
If you have more questions about it, pm me and I'd be happy to talk to you about it.