A Paris court has shut down the nationwide Father Christmas hot line, ruling it exploited young callers at a hefty price to their parents: ads for the service promised a conversation with Santa, but all hopeful tots got was a rcording; a call could last 10 to 20 minutes depending on the length of the story and the number of presents a child requests; it cost $0.40 per minute; the judge said it was clear the recording was intended to prolong each call, a violation of regulations on youth-oriented, pay-per-call services from encouraging children to stay on the line; the jurist ordered SB Communication SA of Aix-en-Provence, to halt the service and banned the publication of its advertisments.