We do not provide a case delete option direct for the client as per privacy and security policy.
However you can simply request to have your case deleted within the case comments.
Simply add to the case comment "I [my name] request this case is deleted from my file".
Your request will be escalated to case manager and the case deleted during a case maintenance run in the future.
Other FAQ's that will interest you:
How do I cancel my subscription?
What is your refund policy?