Terrible!!!!!!!!! – Math Games For 2nd Grade Kids Review

I uploaded the app today for my son. He brought it to me once because the activities were taking too long to upload. Soon after he brought it to me again and there was a blank screen instead of an activity. I received an email from the co-owner of the app about how things were going. I emailed twice asking how do I cancel my trial before billing me $9.99 a month, I have yet to receive a reply!!! I went to the settings and there was nothing on the app to cancel!!!! Can somebody please tell me or help me cancel my trial?
Review by Hekeej on Math Games For 2nd Grade Kids.