I've just looked on my account and I've been over charged on a device that should have finished. It says I've paid £675 on a £600 device plan and I've got no way of contacting O2 to see if they're continuing to take the £25 a month out and to get a refund. Live chat isn't working and no one can take my call when I dial 202. Please help, I can't afford to keep paying for a device that should have already been paid for