Non authorised payment

Hello Sheldon,
Thank you for reaching AVG Support Community.
We're sorry to hear that you’re thinking of leaving our service.
We will certainly check and help you.
We could not find the active subscriptions/trial order on the account that you used for the AVG community. Hence, I have sent you an email requesting a few details to locate your subscription. 
Please check for the email and revert to us.
Thank you for your understanding.

I noticed a payment for £74.99 without my knowledge, how do i go about cancelling whatever its for and getting a refund

Hello Sheldon,
Thank you for reaching AVG Support Community.
We're sorry to hear that you’re thinking of leaving our service.
We will certainly check and help you.
We could not find the active subscriptions/trial order on the account that you used for the AVG community. Hence, I have sent you an email requesting a few details to locate your subscription. 
Please check for the email and revert to us.
Thank you for your understanding.