I am trying out my cellular connection with EE in the UK on my Air 2. (Btw, even though UK, this may affect others, hence posting here.) I remembered from yesterday when I turned off the cellular and went back to wifi, that I had used roughly 250MB and that I have another 10 days or so to use up my 1GB. Anyway, I turned on cellular this morning and it said that my account had expired and I kept getting the dreaded popup to buy more cellular data time. Perplexed I tried the EE website and what a load of use that was! Their best solution seemed to be to go to an EE shop; a 15 minute drive. So back to the Ipad and I went to look at buying more data time -actually to see whether it was 1GByte of 1Gbit I had paid for; it is in bytes. There it said that I had 770MB left; account active and ends in 9 days. But still the Cellular 'button' on settings says expired. If all else fails, either read the manual or re-boot. So re-booted and my cellular account is back fully usable again. So was this an iPad hiccup (8.1.3); EE or what? I don't know, but I thought I would pass on my result in rebooting in case anyone else has similar problems..