Esat Digifone customers were warned yesterday to disregard a rash of hoax SMS messages claiming to offer users £20 of free call credit. The messages read "Send this message to 10 (086) mobile phones and Esat Digifone will give you 20 free call credits at the end of the month". In a footnote, it urges users to log on to the emerge.com website to claim free credit. Emerge is the name of Eircell's web portal, not Digifone's. An Esat spokeswoman said yesterday the messages were bogus and probably created by some young mobile phone users. She said the messages were a nuisance but not harmful to mobile handsets.