The phone number I should use to cancel a payment in my country incurs an additional fee. How can I cancel this unwanted subscription?
online refund https://support.avast.com/en-us/contact/sales/sales#pc
just checked and it sends me to use a non uk phone number as well.
use this link. you can pick live chat or email instead of phone https://support.avast.com/en-ww/index#pc