Inconsiderate McDonald's staff supply Beef burger on Vegetarian Order

I ordered 2 Veggie burgers from your Stoneridge restaurant. I confirmed with the cashier if the burgers were veg. Later found out that the burgers were beef burgers. I am a vegetarian and secondly it is against my religion to eat beef. I am highly devastated as both my wife and I ate these beef burgers, when in fact we are vegetarian. I will not support McDonald's anymore due to your negligence and disregard for your customers.