I understand you want to get a refund for AVG PC TuneUp. On checking your account, I see that you have AVG Antivirus and AVG PC TuneUp. The confirmation email you have received in May was for AVG Antivirus. But the product which has got auto-renewed now is AVG PC TuneUp, both are different products. Hence canceling the subscription for one product doesn't cancel the other one.
I would request you visit https://support.avg.com/RefundForm and fill in the refund request form. Our refund team will process your request [AVG PC TuneUp] and get back to you via email.