well, yes you were lied to, but its not something unfixable. the white dots are not calcium. That's quite possibly one of the most ridiculous things I've heard to date on this forum. But these are still really good looking fish. Those just look like pimples, discus get them when the water isn't quite as clean as they need it. Even professional discus keepers that have been doing this many years can experience a pimple every now and then when they get behind on water changes. For example when I go on vacation and skip several days in a row of water changes, my fish usually get a pimple. I also thing that your fish could benefit to some salt added to their water.