Interest charged with no reason

I've app**** for a FNB Platinum Credit Card and since then, I got 4 statements (Fev, Mar, Apr, May). All paid on the due date, via Debit Order (auto payment solution: Full Amount). I got charged R90.36 interest on March. R216.22 on April. And R141.01 on May. <br> <br> I've contacted my Premier Banker several times but no one seems to be able to provide me any right answer. <br> <br> I got responses like: Cash, Prepaid and Forex/International transactions attract interest from transaction date, which would be ridiculous, considering FNB offers you more eBucks when you swipe your credit card internationally (because then it would be like a \benefit"which must be paid by the customer. Non sense). <br> <br> In any case I asked how could I pay for these specific international transactions I made last week"