drive thru staff are useless

I went through the drive thru on a friday night. Ordered meals for two, one of which was a big mac without cheese. When I arrived at the collection window I asked the lady to please confirm my whole order was there including the no cheese big mac, to which she responded with an irritated 'yes'. When I arrived home I opened the packet to find no big mac at all. <br> <br> I attempted to call them several times to report this. But as expected-no answer. Typical!