Take Away - Milkshake

Went to Spur on the 11/10/2019 to buy a Take away Strawberry shake. Well, 1st of all I dine at spur regularly and order the same shake with my meal. I ordered the Adult shake for R34.90 but was given a small 350ml container( guess thats for kids). I asked the lady is this the adult shake? she confirmed and stated that the container. What puzzled me is when I dine the glass is bigger. I thought its my eyes but Hell No I felt cheated.