Refund declined

I accidentaly purchased a app supscription obd ultimate for car diagnostics on app there says it can be refunded if no features were used and refund time is 30 days.

i requested a refund i got declined but why ? The subscription cost a good 220€ wich is a lot to some one, on the application says it can be refunded when no features are used and the lenght of to request a refund is 30 days max wich i follow the criteria… can some one help and get me a refund