Refund on cancelled subscription

How do I get a refund on my subscription. It was on a automatic payment. The payment was withdrawn in July for a September renewal.

I would like to get the money refunded into my credit card.  I have sent an email previously to the Australian business without a response.

Could you please assist in the process. Would like an email address to correspond with. The adobe home site runs me around in circles.

thanks ....G