The message .com
from "frank spencer" contains these words:

try cleaning it with a pumice stone, any other
advise or suggestions please?

I certainly wouldn't do that. You'll risk scratching the glaze which
will make it easier for the scale to stick again.

It's probably happening because the previous pan let all the water run
out quickly, the new one dribbles a bit. Certainly nothing to do with
guarantees or anything. The simplest cure is one of those smelly things
that goes in the cistern.

--
Skipweasel
Pay no attention to that man behind the curtain.