Oh I've had this problem since end of April 2016 on my mini ipad4. Simcity support has been absolutely useless! Told me it was my internet provider. Internet provider told me it was Simcity's problem. So I'm going around in circles and meanwhile I can hardly do anything in my game. Been stuck at the same level for 3 months as it's extremely difficult to play the game when it keeps going offline. Simcity support won't even reply to my emails any more, been saying they'll get back to me. This is the last message I got from them....
Salvatore (SimCity BuildIt)
Jun 7, 15:24 EEST
Hello Mayor,
To better help you with this issue I've spoken to one of our SimCity BuildIt Support Experts, explaining your situation and passing on your details. They will be in touch to help you further!
Please be aware that the cases our Experts deal with are more complex so ticket turnaround times can be longer than normal. However, we promise to be in contact as soon as possible and thank you for your patience.
Many thanks again!
http://help.ea.com/en/simcity/simcity-buildit/
Sure been an extremely long, long, long turnaround time........so don't hold your breath waiting for a resolution anytime soon.