how do i purchase stuff from psn store with credit card?

ive been trying for the last hour to get overwatch and a year subscription and it doesnt work. ive tried changong adresses, making everythging capitals even making a new account for that one purchase and nothing works. ive tried my moms, dads and my dads work credit cards and nothing. imo if playstation wants people to buy stuff from their online store they should fix the bugs... smh