Hi @Fahim8637 welcome to this free user-to-user Alienware laptop discussion forum. 

Please visit invoice to determine if this Dell Product has Dell warranty. Faulty goods are usually replaced by the vendor. 

Support for Alienware Tri-Mode Wireless Gaming Headset | AW920H, please click on Contact Technical Support and request online session to fix software and/or instigate replacement part and installation. 

If under Dell warranty, please click on the Get help now icon on the right of this web page to start a live chat session. Please click on @DELL-Cares and send Private Message requesting assistance. 

How to Identify Dell Products without a Service Tag | Dell US 

If purchased directly from Dell, then yes, 2 year warranty. If they were broken from a fall, accident, etc., that is not covered. Provide to the GHN (Get help now) agent your Dell order number or Dell customer number.

Yes so I went to get my headphones out and put them on and then after 5 minutes I found that my left headphone had become detached from the band that goes over your head. The headphones are functional but there was no accident to cause this break as I don't take them anywhere and use them at home. 

I have also written this on the get help now section 

Please notify me as soon as possible of what can be done. I am disappointed in the quality and the time it took for them to end like this as I did buy them because they were unique in the fact that they are tri-mode. I also bought them directly from Dell 

I have had this same issue with the left side earphone. I was wearing the headset normal and have never done anything to damage them. I am very careful with them and even have there own place to be put away safely. I was wearing them went to pull the off gently and the left side earphone fell out. It seems like this is a very normal occurrence, but since they only allow you to review brand new products fresh out of the box, there isn't a platform to share this feedback easily.