The Reason Why You Didn't See the Results You Wanted
I'm a licensed Cosmetologist and I am Keratin Complex Certified (another brand of the same type of treatment). Pretty much all the Keratin Treatments are made of very similar ingredients --- obviously the main ingredient being the Keratin. Keratin can come from all different types of sources. But the main difference with the treatments is the method of application. When I was trained I found out how important it is for the Hair Stylist to be properly trained and properly perform the application of the Keratin solution. If excess product is left on the client's hair that can cause it to be weighed down, too straight, and lifeless. If there isn't enough product on the hair then it will still remain dry and unhealthy in the parts that did not get enough solution on them. Also I know with the Keratin Complex brand that one is blow-dried then flat-ironed to infuse the Keratin into the hair's inner layers. If the flat-iron is not used at the proper temperature (depending on the clients hair type and if they have colored or highlighted/bleached hair) it can damage the client's hair from the excessive amount of heat from the flat-iron.
So, I guess my main point I'm trying to make here is that it is most likely not the treatment itself to blame but possibly your stylist ... maybe not that they are purposely doing it right but maybe they weren't trained correctly or are just too lazy to do it the right way :P The solution itself doesn't damage your hair.