Airtel — wrong recharge, i need refund

On july 5, 2020 i recharged my grandmother's number online and then i realised that one number was incorrect. So some other person's phone got recharged by me accidentally.
I e-mailed airtel, and they told me to give details. I gave them all details like wrong number, transaction id etc.
They told me to call 121 and talk to the customer executive for providing more details. So i called them, but the customer representative asked that they cannot help me.
So what is this happening? Resolve my issue, i need my money back. I also called the person whose number i recharged accidentally. He said that he has already a yearly plan so that plan is totally waste for him.
Kindly resolve this issue asap.
Also i am sending screenshot of the wrong recharge.