declined my refund

i ordered a back support thought that it might help me with my back pains i wore it for 4 days and discover that it makes the pain worse so i send it back for refund then they tell me its been worn now how does a person know if its going to work or help if you dont put it on to see if there is results or not now refuse to refund me my money because its been worn what the hell they quick to take your money but when you have a problem with the product they dont want to refund you they will rather decline your refund now they want to send the item back to me but its not working or helping this is so must bull ****