For a follow up, not that anyone cares...
I got a letter stating the charges would stand, that the merchant basically said they did the work so it was valid.
I phoned customer service to question how that could be, as I was still having issues and have to basically shut off the water valve every time I use the toilet. They said OK, please file a complaint in writing, and send it to the corporate office for an "escalated" dispute. I have added pictures to the letter, but now I am stuck via snail mail while I wait for this to get worked out.