Automatic subscription renewal

I signed up for a 6 month contract. I during the period did not really use the app as it did not meet my needs. They then summarily decided for me to automatically renew my subscription without my permission and have since deducted the funds. This is unacceptable and is poor business practice. It is tantamount to *****ing. I would like to be refunded in full for the wrongful and ********* way in which the subscription was renewed.