Did a commercial last week in some offices and training rooms, customer was very pleased but

See email below :
Hi, Steve,
You'll never guess - in addition to the new coffee stain that I told you about, we now have yet another. This latest is not far from the one you lifted and about the same size so we are sure we have a
phantom coffee spiller who is not owning up to their carelessness. It is SO annoying because it was looking so good for such a short time.
I tried the spray you left me on the first (2nd?) coffee stain, but very little, and it doesn't seem to have done any good. I'm itching to get in there with some oxy or carpet cleaner or even vinegar as you suggested, but I don't want to put the wrong thing on for you to eventually have to struggle with.