My wharfedale subwoofer just made a disturbing niose and now it has no power getting to it. I have checked the fuse and this isnt the problem. I bought it last december so it should be under warranty. The problem is I seem to have lost the receipt. I bought it from sound and vision. Will they take it back for repair even though i dont have the receipt? The annoying thig is when looking for the receipt I have found the receipts for every other peice of my set up.