Staff that can't count or understand english

10 min drive to mcd, 10 mins wait in drive through. I order 3 cheese burgers and a bigmac meal. I get to the final window and ask the lady twice if she packed 3 cheese burgers. She says yes, I ask again, she smiles and says yes. I get home there is only 2 cheese burgers and a half packet of large chips. This is why I never buy from this mcdonalds. Useless staff can't do such a simple thing.