Read the muriatic info page => http://pool9.net/ma/, then get a jug of muriatic. (Lowes, etc.)

Pour a small amount of MA in a plastic bucket -- watch for fumes! Put the bucket next to the pool near a scaled spot. Wet the deck down, so acid splatters don't mark the deck; leave the hose running next to you, so you can quickly rinse away splatters.

While wearing gloves and glasses, wet a clean plastic sponge (no residue to react with the acid, and no cellulose sponges!!) with acid. Take the sponge, and hold it against one of the scaly spots. If it fizzes or is removed, lowering your pH will accelerate scale removal.

If that works, then read about lowering alkalinity, here: http://pool9.net/alk-step/

Meanwhile, if you can, purchase a K2006 testkit. With the pool guy you've got, you need one so you an monitor his actions. http://pool9.net/testkits/