I’ve been playing sand balls for months now, I only had the bank and police station to unlock at..

I’ve been playing sand balls for months now, I only had the bank and police station to unlock at this point. I had well over 1 million diamonds. I was working on the Ferris wheel in sand city. I was on level 4 or 5 on my vehicles. One day I went to play and it was a completely different game style. Like challenge island, candy island, fruit island and a couple more but not sand city. How do I get back to the sand city game where I have played to build my town?