They did not have any steak. Steak is sold by weight, so you buy 2 kilograms of steak (plural is within the kilograms). Sometimes you buy for example three pieces of steak, but generally you would not ask for 3 steaks.
Why did you go to the butcher's shop in main street? or Why did you go to the butcher's shop along the main street? When the street is called Main Street, you can say: Why did you go to the butcher's in Main Street?