Free Minecoins...?

Whenever I go to look at the prices of minecoins it says that someone has started a purchase on the computer and it says "would you like to continue?" and then you get the option of yes or no. when i say yes it gives me minecoins. When i go to look at the charges of my account later it says i have not bought anything. Oh and that purchase that shows in the pic is another time i got minecoins. The minecoins I got were not listed as a prise