How can I cancel Dell Microsoft 365 autorenewal subscription

I have received an email saying my Microsoft 365 autorenewal will be billed in a week.  I want to cancel it.  I log into my digital locker. I can see the subscription, but there is not an option to cancel.  I try calling dell support, and the automatic response says for me to log in to my account.  I am so frustrated.  I want to talk to a real person.  I want this canceled.  I do not want to be charged $72 for something I haven't used in years.  Please help