HarperCollins Customer Service Issues

I was charged $27.37 on my Visa without authorization for a trial book that I only paid $1 for. Even after requesting cancellation, the charge went through. I have five grandchildren and could have considered keeping it if the process was more transparent and with my approval. I want both the $27.37 refunded and the subscription cancelled. If this issue is not rectified promptly, I will escalate it further to ensure my refund for unauthorized charges. I hope this can be resolved as a mistake and that I can revisit your services after a proper review period of two weeks. Thank you for addressing this urgent matter promptly.