Ouch your client! I had one earlier this year like this. We were doing some audio processing for word matching, he had also been mislead before coming to us, he fully believed that this was going to be some form of super AI trained on his 5 audio records of him repeating the words over and over...

We did all we could to steer him toward a correct path of understanding. Sadly we launched a working product but he doesn't understand it and continues to miss represent and miss sell it.

After continuing to give him time and follow up with him (I tend to personally do this with Clients like this), I can tell he is starting to realize his lack of understanding...