i went to a free ringtones site and i put my phone number in and they sent me a txt?

[ZoeyOsborne]

i went to a free ringtones site, and i put my phone number in, and they sent me a text saying you can cancel your subscription anytime ....just text stop .....so i did as soon as it sent me that .does that mean they charged me ....they didn't get my credit card number or anything