Apple charged my account for a Cancelled subscription.

How do I get my money back in the quickest way? The subscription was cancelled right away, after first getting the app (didn’t need it), fast forward to 6 days later, I was charged for it. Even if the subscription was still to be kept (which defeats the purpose of it being cancelled) they charged me on the 19th for something that wouldn’t have been due until the 22nd. So they charged me early for a cancelled subscription. Like make that make sense. (I REPEAT, the subscription was cancelled day 1, and was charged to my account on day 6 for something that WOULD have been due on day 8, yet was cancelled back on day 1)