Changed outside antena ariel

The car went for repairs and when it came back the outside antena/ariel was removed. When I returned the next day I was given an antena that was obviously not for my car. It differs markedly from the one my car has before they took it in for repairs. I was told it is the only antena they have so is mine. The antena is not for my car and is longer than the original one. I was promised they will look for it and contact me which has never happened. I am really sad because my car does not look good with this antena I was given.