I don't think that's the main problem, it's the fact that the systems aren't connected to each other - maybe the move back to UK will help that though.
I recently moved from an Orange PAYG to an EE sim only package. First, EE didn't transfer my old number, despite the EE store saying that they'd sort all that out. Took a call to their India call centre to fix that.
Next, I'd signed up to a special offer - 16Gb Sim package, that was usually at £35 a month, on offer at £19.99 a month. Can you guess what price my first bill came in at? Yep, £35. This took a trip to their store in town (which despite reassurances from the guy in store that it was just their system and they'd only take £19.99), they still took £35 out my bank account. He practically admitted to me in store that it was the way their systems were set up. The fact that T-Mobile and Orange were part of the EE brand you'd be forgiven for thinking switching from one legacy package to one of their EE packages would be seamless. Not the case at all. The EE website said one price for my billing, the EE iOS app said something else - apparently, the app can take up to a month to update its pricing - WTF, in the age of superfast broadband it still takes a month, are you kidding me?!
In both cases above, they were resolved by calling their India call centre - the UK staff/systems were useless in my experience. I fear things will only get worse if BT get their grubby mitts on EE, as is rumoured.
