Parts help

As he heading says I'm looking for help. I ordered a drivers under side floor pan shield (big black plastic bit) from Arnold Clark In Inverness on Monday. Drove through from elgin today to pick it, guess what it wrong,it is very similar to the one on the car apart from a 18' inch by 9' inch rectangle hole cut in it under the drivers seat area and the kick down at the rear has fins on it and mine is smooth. The fins at the rear kick down part don't bother me but why is there a huge hole cut in it, does this not kind of loose the whole point of the shield.any help, advice or a part number is more than welcome.