I recently bought a Samsung A25 mobile phone for my son and put his existing SIM card in it. Everything transferred over no problem and he's been using it without issues. He has a Giffgaff plan which gives him 20GB of data each month.
Yesterday he tried to connect his data and it wouldn't work. When he checked the settings it says he's used 6.6Gb this month. It has a 2 GB warning underneath. I've checked his Giffgaff account and it says he's only used 11 so far so still has plenty left in his plan. We've tried turning it on and off, putting the WiFi on and off with no joy. Does anyone know what else we could try?