What can I do if my credit card got charged even though it said "payment is canceled" on T-mobile's web page?



    Last week I tried to a payment to refill my account. I tried twice with my card, and it popped up and said: "your payment is canceled and your credit card won't be charged." Then I tried another card and successfully made my payment. A few days later, I found that my first card got charged twice by T-mobile and it could not be found on my account's activity page. I called to customer care about it, and they said they could not do anything even if I had the payment IDs because the activity is not shown on my account. What can I do to get a refund for this?