Giffgaff is a low-priced mobile provider offering a range of great-value Sim deals. How did its customers rate it? Before signing up for a new phone deal, read our review of Giffgaff to see how it did ...

The problem occurred because customers who bought a Giffgaff "goodybag" bundle - comprising voice and text minutes as well as data allowances - using their prepaid credit, were overcharged.