Hathway Hyderabad - After Router return also Hathway team doing mental torture

I haven't received any Acknowledgement No from Hathway Office Gachibowli(near DLF Cyber City) while giving the router to Hathway Gachibowli office on DEC ****. I don't understand why they didn't give it to me.

I am receiving a call from the mobile number - ********** again. I am attaching audio received from this number how they are doing mental torture to me after returning the router also and daily i am receiving calls from Hathway.

I have included @consumer-complaints email id, while I have initiated the email after the router returns in Dec month ****. But the Hathway team is asking for an Acknowledgement Number now on March ****. I don't know why they have delayed upto this time and finally doing so much mental torture to the customers in this way. Please listen to call recordings of Hathway Customer care how they are dealing with customers even though they were not providing answers to customers that Router has given to Hathway office also.

I am requesting you to please solve my problem by contacting the Gachibowli office. While asking them seriously they have provided only this video.