Can I request a refund for an unused application?

Re: " I need your help. I never use the application. Please make refund me."

We are all Apple users, like yourself in the community, so no-one here has access to your accounts or details,

A cancelled subscription may not expire until the subscription period that was paid for ends.

You can try: Request a refund for apps or content that you bought from Apple - Apple Support

Else: The best source of help for a product not made by Apple (a third-party product) is the company or person who made it—its vendor or developer:

How to: Contact a third-party vendor

Contact a third-party vendor - Apple Support

or

If an app-developer has your money (ie not Apple)

How to contact an app developer - Apple Support

If more support is needed: See Apple Support' website for: Subscriptions and Billing - Official Apple Support