Am I entitled to reddress without proof of purchase? Faulty please help :)?

I bought a pair of Coloud headphones about 2 months ago in HMV. I always had a feeling the sound was a bit off because it would shake about if I moved the jack when it was plugged into anything. the problem is now the sound is gone completely, and I burned the receipt and the box it came in! The good thing is that the headphones came with a year's warranty from the manufacturer, but whose responsibility is it to address the problem; Coloud or HMV? And will I receive a refund/replacement without proof of purchase? Please help :)