I had the same situation once. I had been made to promise two dates and so I did. The first date was dire. I just couldn’t face another couple of hours with this girl, not so good looking and really boring personality. I felt a little mis-sold. There was absouletly no way I would ever marry her, even though she was a nice person.
The shadchan put a lot of pressure for the second date, I said no no no and eventually when I had run out of excuses I said I just don’t find her attractive he relented. I am sure from what he said he had an eye on the shadduchnus gelt. Oh well!