We won't take it back

On the 2/02/215 I bought a Bluetooth earpiece. When I started using it, the sound was very bad compared to my previous (lost) one. I took it back on 3/02/2015. The lady in that department asked to test it said she doesn't hear anything wrong with it. I told here that I have used Bluetooth for years now and the reason I brought this one back is I cannot bear the sound of it. She went to the back and told me that \sorry the manager said we cannot take it back because of hygiene issues". I told her that I wouldn't have bought it if I was told that I return it and we are not allowed to test them before you buy. Now she had put it in her ear and now I must accept and not have any hygiene issues. Then she phoned the manager and I realised from their conversation that she **** before when she said the manager said they can't take it back. After taking back I wanted to buy a Samsung one . She told me that it works on Samsung only and everyone who bought it for other phones brought them back (surprisingly they never had hygiene issues on them)"