How to verify payment?

I don’t know how to verify my card on apple. I have been trying to figure it out for weeks now and everytime I try to make a purchase it says the purchase fails, but IT STILL TAKES MY MONEY. I have made multiple reports about this and had no response, I have tried $1 type payments to see if it ever gets fixed because this started about 3 weeks ago, easily. I have lost about $50-$60 because of this and it very frustrating. So I just wanna know how to verify my card so I stop losing money, I do use a Greenlight card( stupid, IK. Supposed to get a real card in the next year) so Idk if that has anything to do with it but still all the transactions go to apple which is what my notification says everytime I attempt to make a payment and lose my money and don’t receive what I paid for.