Cancel dell renewal fees and account

Hello I have a Dell account that I would like to close I received once again a Dell renewal fee of $99.99 and I am trying to call to cancel it I have tried canceling this three times now and thought that it was taking care of and I guess not and my bank just informed me that the payment was trying to go through on my Dell account I just spoke to someone yet again I'm online I can't find out how to cancel it so I need help please