Just done it. They say there's no cap on data on my account but that I should visit an O2 store to have both the phone and SIM checked for any further advice. Can't say that was massively helpful lol. I don't see how it can be the phone when I used this phone with the talkmobile SIM no problem.
Not sure what they'll be checking but would a carphone warehouse be able to do the same checks? There are 2 CPWs much closer to me than the nearest O2 store.
They wouldn't replace the SIM, but could I do it myself using the SIM swap if I order a new one? I did actually order a new one to do that last Monday via webchat but the SIM never arrived (and tbh I'm not sure I trust their knowledge on SIM swaps either)...I know the weather was bad then but it it should've been here by now, we've had post again since Thursday. They did give the option of them doing the SIM swap, posting it out and cancelling my current one within the day...glad I didnt go with that option!
I've also just read this below, it doesn't mention using Android on PAYG. Not sure if it's just poorly worded or if it means you can't use it with Android?
Setting up a personal hotspot
To use your phone as a personal hotspot, you’ll need a 3G or 4G connection.
For Pay Monthly customers, if you have an iPhone or Android, simply switch Personal Hotspot on to get started.
If you’re a Pay As You Go customer, you can now tether up to five devices on your iPhone if you have:
On Windows Phone, you need to go to Settings, then tap Internet sharing, Share over, and Wifi. Then make sure Sharing is set to On.