I just bought a very expensive headphone 3 days ago. Just yesterday i realized a significant difference between the left and right earbud of the headphone, both the bass and sound of the left earbud is higher than the right ear bud. It's a little but drives me crazy and does give a headache. I'm thinking about returning this headphone to the store from where i bought it and expecting a replacement, but i'm not sure if they would take it because i lost my receipt. Would they accept replacing the headphone without receipt verification?