Mobile phone group Giffgaff has been fined £1.4m by regulator Ofcom for “unacceptable” billing mistakes that saw 2.6 million customers overcharged. Ofcom said Giffgaff, owned by O2’s parent Telefonica, overcharged people up to a total of almost £2.9m. “Getting bills right is a basic duty for every phone company,” said Gaucho...