Rob why have you let it come to this! I can't understand.
I bought an item from you, its unused never fitted to the car but it has a fault.
In future I would check your items properly before any decripsion is made.. it makes good business sense.
Set up a clear refunds policy so issues don't happen like this.
This is the first time this has ever happened to me.. It would have been so simple to return the faulty goods, instead you bite your nose off to spite your face and you loose us as customers.