Why don't Protestants have mass?

To Protestants, mass as understood and conducted by the Roman Catholic church represents beliefs that are not founded upon Scripture. In particular, they object to the doctrine of transubstantiation, that during the mass the bread and wine are transformed in essence into the body and blood of Jesus. For one thing, this says (to the Protestants) that the sacrifice of Christ upon the cross is being re-done, that his original death on Golgotha was not enough to completely pay for all of our sins.