Refund Issue

Hi Yesterday I purchased the one month free trial of the Musescore and they charged me 29,99. Thr very next moment I cancelled the subscription and requested the refund and what they said is they can just give 30% refund for not even using the features for a day. What should I do now. I was really cheated. I’ve attached the copy of the email.

I think I will have go see through consumer rights for this.

Any comments will be appreciated.
Thank You