Is there any way for me to cancel my subscription and have my money refunded if I cancel in less than 24 hours?

I had autopay on. I finished my GRE on the 30th and I was under the assumption that it would get cancelled automatically after the billing period. But it just renewed my subscription automatically. Could I get it cancelled?

You can cancel anytime, but your subscription will remain active till the end of the billing period and cannot be normally refunded.