AVG Subscription Refunds

I foolishly subscribed to by AVG AntiTrack for Mac when I responded to a pop up on my screen. I ordered this software product on Sunday 9th January and I received a response stating that my order number was 1093344964439 and the cost was Australian $44.28.
Within half an hour I realised that I already have similar software on my computer from another provider, so I cancelled my AVG order and received an email from AVG stating "You’ve successfully unsubscribed from AVG Internet Security (Multi-Device). This means you’ve disabled auto-billing, and we’ll no longer bill you for this subscription".
Unfortunately I have just checked my credit card bill and I find that the software was charged to me, despite AVG stating that I would not be charged.
Why have I been charged and why have I not had a refund? I really would like a refund please. I am a pensioner and not tech savvy, so how do I get a refund? I have tried to find an email address for AVG and cannot find one, presumably because it would be flooded with complaints like mine! 
Do the decent thing and refund me please.

Hello Geoffrey,

We are glad to look into this and help you.
We request you not to share any of your personal or sensitive information over the public forum.
Regrettably, we don't have a designated email address that can be used to contact us. However, we can send you an email and you can revert back to us.
We have sent you an email informing about the AVG product details and please reply to that email for further assistance.
Thank you.

Hello Geoffrey,

We are glad to look into this and help you.
We request you not to share any of your personal or sensitive information over the public forum.
Regrettably, we don't have a designated email address that can be used to contact us. However, we can send you an email and you can revert back to us.
We have sent you an email informing about the AVG product details and please reply to that email for further assistance.
Thank you.