Nykaa - Delivery Package handed over to unknown person without checking with the customer

I had made an order on Nykaa **th June, I realized that I entered the wrong address but since they don't have an option to change address after placing the order also due to covid ** they are not accepting returns so I checked other alternatives.
As per their cancelation and return policy, you can refuse to accept the package at the time of delivery, it'll then be dropped back by the delivery person to their warehouse and they will refund the order amount. This seemed like a good option so I was waiting the delivery day.
On **th June, I received their automated message with OTP details to be given to the delivery person at the time of delivery. I was waiting for a call from delivery person but I didn't get any call. In the evening, I checked the app and saw that my package has been delivered and there was no detail of whom it was handed over to? and why I didn't get any call.?How were they able to deliver without getting the secured OTP from me?
Same day, I raised this concern with them and was told that it'll be resolved in * days. When I didn't hear from them by ** June, I wrote to their grievance cell. I got a reply that they'll take *-* days to check and get back.
On **st June, they replied to me with a delivery receipt with a signature that I do not identify and I told them so. I again requested them to check what OTP was entered in their system. I got their reply on **rd June saying that they can't help me with this query because TAT (turn around time) has been exceeded. I asked them for an escalation point contact but they have not been responding to me ever since.
Please help.