My partner and I did this yesterday, saving around £1,000 in doing so. To cut a long story short, we found out that 3 UK are going to increase the amount they are charging for non-direct debit customers to pay their bills, from £3 to £4 a month, plus they are going to charge £1 a month for paper bills. The only way to avoid the paper bill charge is to switch to an on-line e-billing system, and the only way to go onto an e-billing system is to go on direct debit.

We argued that this left us at a disadvantage from when we originally signed our contracts, so we wanted to exercise our right to leave the company, and cancel our contracts, without financial penalty. We were told we couldn't do this, and were stuck with this, but we took it further.

We contacted the press office by email on Monday evening and the next morning my partner received a call from them yesterday (Tuesday) morning, telling him to expect a call from the CEO's office, the Chief Executive. He rang, and after much discussion, he agreed that the situation had been mishandled by the call centre staff and we were perfectly within our rights to leave, which we have done.

We have given 3 a month's notice (30 days), and after that, we are gone, with only the outstanding balance to pay. The rest of the contracts (around 10 month's worth) have been cancelled without us having to pay a penny in termination fees.

Needless to say we are thrilled to bits. I hope this knowledge helps someone who may wish to leave 3.