I want my refund of my last purchase because I just cancelled it so kindly refund me back immediately

If you have received an invoice from Apple, on every invoice from the Apple Store and/or iTunes Store always states what you have purchased (and/or concerns a subscription) and the amount.

Tap on Report a problem on the invoice.

Or try to ->  Request a refund for apps or content that you bought from Apple.

Request a refund for apps or content you've bought from Apple – Apple Support (UK)

If you have requested a refund, you must wait until Apple has approved. Then you will receive a message from Apple.

Refunds are not guaranteed. For more information, see the Terms & Conditions.

Contact Apple. Try using this link. https://idmsa.apple.com/IDMSWebAuth/signin?appIdKey=20379f32034f8867d352666ff2904d2152d5ff6843ee2db5ab5df863c14b1aef&path=%2F__logged_in%2Freportaproblem.apple.com%2Fstatus&authResult=FAILED