Please help me understand this vial.

Ok so I joined pom health for the vial sale. I just received a 20 mg vial that's 2 ml.

I bought the 40 mg!

I sent a message saying I only received 1 20 mg vial. That does not equal the 40 mg vial I bought.

I sent an inquiry to one of the nurse providers on the platform and he said

Hello T####### Thank you for sending these pictures in. You receive a much more concentrated vial at 20mg/ml. By my calculations, 20mg x 2 ml = 40 mg.

How does this even make sense???