I can tell you're pretty mad.
First of all, It's Custom Building Products, not Capital. The Home Despot.....ah..ah Depot sells it. I don't think it's any worse than any other mastic however. What did you use it for? What kind of tiles, wall or floor? Who selected the product?
Mastic should only be used for vertical installations on dry areas, and never to install tiles on floors, wet or dry....never.
Yes, you now know that most manufacturers of these products have a problem telling the truth. They all lie about the use of most mastics. And you also know those store have buyers that have no idea what products are used for. All they know is how to force the manufacturers to give lower and lower prices. The buyers in the tile department don't know much about tiles.
As far as the big box store go. Most of the people there start out know nothing about tile or floor coverings. They learn as they go, and most often they learn to recommend the wrong products. Didn't you know that most of the workers there don't know anything? Why did you buy your stuff there? Why didn't you buy the materials at a real tile shop?
Well, I know the reason and I must admit I shop at those places too. I just never ask for advice, not even which aisles things are located.