Vitality Money and Credit Cards

I opened a transactional account in September and had awesome service. I have Discovery Money and was reaching my spending goals and reaping the rewards. In February I opened a credit card to use for my petrol expenses. Now it is my primary account, which nobody informed me and I lost out on a minimum of 132 discovery miles. I realize for alot of people it is nothing but for a teacher who is trying everything to save money, it makes a big difference especially since I am paying a subscription fee for Discovery Money. I would like to cancel my credit card with immediate effect and will be opening one with Capitec.