Adam French, Which? Consumer Rights Expert, said:
“Huge numbers of Three customers have woken up to find they are unable to make calls or use roaming data and will be left feeling angry and frustrated as a result.
“The mobile operator has to do right by its customers by keeping them informed, ensuring no one is left out of pocket and we expect those affected by this lengthy lack of service to be compensated.
“The UK is already lagging behind the rest of the world on the provision of 4G. Failures like this will only intensify the pressure on the government, industry and the regulator to up their game and ensure we get a decent service.”