You can not buy the KIT, but you can buy the rank and that gives you McMMO Credits. By buying the kit, I am thinking you probably bought it from someone, and thought they would also give you McMMO Credits. That person has successfully scammed you, as kit Merchant is one of the easiest kits to get.
yeah i meant getting the rank. sorry about that, but yeah, i did not get the credits from purchasing the rank for kit merchant. i went to the sign and clicked on it and it took 30k from me to purchase the kit if that helps you any to see how i got it.