Hmmm, it's happened to me today and I think I know why. When you / I upgrade with EE we keep the same monthly account reset date as before. So, if you upgrade just a few days before this reset date then you will be given half of the new 160 GB immediately. And at the reset date you'll get the other 80 GB of data. BUT there is no rollover. So, you'll just have 80 GB that first new full month and then 160 GB from the next month onwards. It's annoying, yes. EE should give pro rata data in the first few days of an upgrade until the first reset date - but it doesn't. I've had this happen on previous upgrades with EE, too. I'm not going to argue the point with an EE operative though. It's not worth it. If you want to argue this with EE then do so and let me know if you have success.
