Varun Motors — Missed body cover in showroom while furnishing seat covers

I had purchased Maruti Swift vxi model.while furnishing seat covers body cover missed.After that we went out of station on some urgent work.Meanwhile we contacted the showroom person about missing body cover.He told that after that comes to showroom discuss with the manager.Now they told that we cannot do anything.If missed the acceries in ur premises who is responsible.It was not the matter of money.If we loose confidence how should we give for servicing.