cancel subscription!

Cancellation gets confirmed by e-mail. To cancel go to https://account.adobe.com/plans and click manage plan and click cancel for the plan you need to cancel. You need to be logged in with your Adobe ID.

Adobe did charge, not Acrobat. Acrobat DC is the product and does not cost 70-80$ per month as a subscription. So this is going on for more than one month. I check my credit card balance at least weekly and I get notified for every charge. 

This said, I recommend you to contact Adobe customer care to negotiate your way out of your one year subscription contract. Adobe customer care can be contacted by beginning a secure chat session at https://helpx.adobe.com/contact.html?rghtup=autoOpen. Pop-up blockers need to be disabled! If the chat window fails to open, or is non-responsive, use a different device to start the interaction.
Support phone numbers may be found here: https://helpx.adobe.com/contact/phone.html. Please note that phone charges may apply.

(see also here: https://community.adobe.com/t5/creative-cloud-services/how-to-contact-adobe-support/td-p/11875703 or here
https://community.adobe.com/t5/account-payment-plan/how-to-contact-adobe-support/td-p/11843852)