Hi @Yuvraj_Maru4580,
Hope you are doing well. Sorry for your experience with Acrobat Reader Mobile.
I checked your account registered with the community and saw that the subscription is still active on your account.
The free 7-day trial is available only when you opt in for the annual subscription. You were charged because you availed of the monthly subscription.
To learn more about cancellation, please click here: https://adobe.ly/3ZvjKjN
Also, to start the refund process, please visit the link below from Google: https://adobe.ly/44eX8qe.
Hope this clarifies your question.