Its the wrong color

Last week, I brought a blue Bmw and I got an email today saying its ready to be picked up at 3:00pm. So I hurried into my mum's car and she drove me to the dealer ship. When we got there we saw a brand new Bmw but it was black so I carried on walking but i could not find a blue Bmw. So we went to the man at the desk and asked where my Bmw is he showed me it and it was the wrong color! it was black not blue! I am so dissapointed.