Pratley Pearl retrospective application does NOT WORK

One would think that dealing with a trusted brand will give you some comfort, however my experience with Pratley has been one where they do not take the time to understand the issue or consider the possibility that their customer could be correct. I had bought the Pratley pearl product to apply on top of my plaster for the benefit of insulation. I was given the assurance that the product will work and this retrospective application was possible. My contractors were provided training on the application by the Pratley representatives. A few areas were app**** in the presence of the representatives, and the training was also done on the property. A year later, some areas started cracking and we had to remove the application. I contacted Pratley, and the reason given was that the application was probably not done correctly. Another year later, more areas started cracking and had to be removed. Called Pratley again, and received the same reason. A further year later, the areas that were app**** in the presence of the Pratley representatives started coming off / cracking and had to be removed. At this point, all the Pratley pearl app**** has been removed. Pratley is still denying that the retrospective application to plaster does not work. I have also them to provide me with references from applications, and to date they cannot provide this.