What is the formal complaint procedure for someone who is experiencing literally the WORST customer service I’ve ever had in my entire life over a warranty issue?

All I can get is webchat people who promise me supervisors will contact me and never do and a support team that lacks the slightest modicum of common sense. 

My Blackshark V2 fell apart while it was on my head, and I can’t get anywhere with a warranty replacement because I don’t have the bloody “original charging cable” as if it has anything to do with the fact that the headset literally fell apart during use.