Azure imgine cup

Question

I used subscription only for Microsoft Imagine Cup Learning, and cost is either by mistake or unintentional and not used for commercial purposes. They might reverse. 

Last month I was deducted $65, I tried to take off my card but they told me I had to cancel my subscription, I cancelled my subscription last month and I didn't use Azure during this period but I was also deducted $405.

It was just for the competition and I didn't know what to do. The lecturer said put the cards in and don't worry. It won't withdraw any money. I didn't expect this to happen.