All progress lost and reset to start!

All of the airports have been reset and my golden aircraft have been lost. I had progressed to Nagoya and was half way through the passenger numbers to unlock San Diego. Over 20 golden airplanes and I have spent money to purchase these and more. Please can you advise how to resolve this?

I’m using an iPad, there has been no changes in accounts. It was working fine, I closed the app and opened it 30 mins later and it had reset back to the start.