After reading @gindygoo post I thought I'd share my experience of getting a refund. I bought a Three Paygo data sim and Three mobile call sim to take to Australia to take advantage of their Feel at Home service. Got to Australia and the sims would not register onto any network. Tried for 3 days and decided to buy a Telstra Paygo sim. Googled to see if anyone else was having problems using Three in Aus and it turns out Vodafone Aus was having problems registering Three Paygo sims onto it's network, Three contract was not affected. The problem was resolved the day I was due to fly back. I heard of this service called www.resolver.co.uk a few months earlier and decided to put it to the test. I'll let you look up what they can do, the service is free and Three refunded me £50 when all I was expecting £15 as I still had 2 months to use the data sim. My friend used it to get all her unauthorised charges refunded on her orange phone even though she was liable for them, but she asked orange to provide her with a list of the premium rate calls, the amounts and the addresses to write to, Orange said she should Google the info and on this technicality, orange executive refunded her. Resolver is not just limited to mobiles.