I've just received a phone call from the number 013*********. Caller ID identifies the number being that of Fetcham Fish Bar, located in Esher. There is such a restaurant, located in Leatherhead, and this is their number. The gentleman on the phone offered me a 25% discount on my current plan. Immediately, it sounded too good to be true. I queried why the caller ID shows him calling from a fish restaurant. After I insisted on going into a Three Shop in person for any upgrades a second time, he abruptly hung up.
The whole thing feels... fishy, pun absolutely intended.
