How do I cancel my auto renewal?

On 9/13/2017 I was charged $84.99 on my AMEX credit card with the description of "AVG*AVG SUBSCRIPTION ****"  This is an auto renewal for a service I haven't used in years.  The computer it was placed on long ago died.  I need to cancel auto renewal, but the email I used back in the day to set this up was either *************** com and both accounts are long defunct. Due to the fact that I don't have access to these emails anymore, I can't log into AVG to cancel this auto renewal.  I contacted AMEX and they will block this charge on my card, but I need someone from AVG to please help me to cancel the auto renewal so that I don't have to call my credit card each year to block the charge.  I have created a new AVG account with my current email of *****so I can use this forum.  Thank you in advance for your assistance.

Hi Nate,
I can understand how upset you must be.
I understand that your AVG subscription has got auto renewed and you would like a refund for it. I will certainly help you with it.  The account is located under *********
When you purchase an AVG subscription (formally known as "Continuing Protection Service"), the subscription will continue until you have cancelled it. Customers will be billed 15 days prior to the start of the next subscription period. Customers will also receive an email regarding the automatic extension of their AVG subscription, 45 days prior to the start of the next subscription period.

Please visit https://support.avg.com/RefundForm and fill in the refund form and submit it. Upon successful submission, our refund team will process your request and get back to you via email with in 7-10 business days.

Hi Nate,
I can understand how upset you must be.
I understand that your AVG subscription has got auto renewed and you would like a refund for it. I will certainly help you with it.  The account is located under *********
When you purchase an AVG subscription (formally known as "Continuing Protection Service"), the subscription will continue until you have cancelled it. Customers will be billed 15 days prior to the start of the next subscription period. Customers will also receive an email regarding the automatic extension of their AVG subscription, 45 days prior to the start of the next subscription period.

Please visit https://support.avg.com/RefundForm and fill in the refund form and submit it. Upon successful submission, our refund team will process your request and get back to you via email with in 7-10 business days.

Akash, Thank you for the help, however I still need assistance.

Due to the fact that I don't have access to the email (******) that I used to orriginally purchase the product I cannot locate either the reference number or the license number/product key required to successfully submit a form to the refund team and to cancel this service via the link you provided.  I also no longer remember the password that was associated with the account I orriginally set up with AVG under that email so I can't access them that way either.  Sending a password reminder to the old yahoo email account does me no good.  I would still like to cancel this auto renewal.

What are my options from here?

Thank you again for your help.