I paid for something i didn't received (One One data Product)

I have an account with Markham and i joined the one one product then after two days I decided to call them and cancelled it, then I wrote a review on hellopeter then they give me a call, promising me that when I get to the store i won't pay the product but I end up paying when I visit their store in Midrand because I was protecting my name, I'm not happy because I paid for something which I did not received or use.