Have had so many issues, I can't be bothered to put them all here, but customer service is dishonest and unhelpful in my experience. Have switched between O2, Vodafone and EE over the last few years. EE weren't great, and Vodafone even worse, but O2 are one of the worst companies, let alone mobile providers, that I've ever used. Will leave my contract as soon as possible and go back to the lesser of all evils EE.