How to cancel my avg subscription that i never authorized for?

So, I logged onto my paypal website and apparently Digital River took out $77 from my personal bank account and I never once signed up for a subscription before. Now all of a sudden I am seeing a unusual charge for multi device AVG and I don't even pay that. I only signed up for the free version and then I uninstalled it because I didn't like it… Is digital River a fraudulent company? I would like to know how to cancel this subscription. I have no options in my dash board.

Hello Martin,
Thank you for contacting AVG Community Support.
We understand that you wish to get refund and cancel your AVG subscription.
We are really sorry to know this. We'll certainly check and help you out.
As it isn't advised to discuss personal/account related info here, we've sent you an email with further details.
Please check your inbox/spam folders to find the email and use it to get back to us.
Thank you and keep us updated.

Hello Martin,
Thank you for contacting AVG Community Support.
We understand that you wish to get refund and cancel your AVG subscription.
We are really sorry to know this. We'll certainly check and help you out.
As it isn't advised to discuss personal/account related info here, we've sent you an email with further details.
Please check your inbox/spam folders to find the email and use it to get back to us.
Thank you and keep us updated.