Account charged for no subscription

Hello, I just been charged £29.99 from avast, even though my account has no subscriptions or payments visible on my account page. I do not want any subscription, I did not sign up for any renewing. I have no order number because I have no subscriptions or previous payments visible on my account page as mentioned before. Before I contact my bank for unauthorised payment, is there anyway I can get this refunded. There isn’t even a UK phone number to call even though they have offices in London?

https://support.avast.com/en-ww/article/Refund-request

Thanks for replying, but like I said I cannot do a form for a refund, as I have no order number - it’s not visible on my account page at all

You’re welcome. Just enter/use 00000000 (Order-ID) and explain it in your request.