Refusing to take responsibility of faulty product

After a few months after buying new headsets at cash crusaders, sound quality started fading then i could only hear with one side, then not hear at all. I returned these cz there were still on warranty and was told they'd be sent for repairs. After keeping then for over a month, cash crusade now tellss me its the damage is due to consumer and not theie responsibility. They are just ***** who refuse to take responsibility for the low quality of their products. How did I abuse headsets that I only use for work purposes