You can go up to the 75th level. It is possible that your device memory is full, therefore game starting to repeat. What you need to do is to clear App cache, and when you play try to remove background apps. If you have problem please let me know what device you use so i can give you better instructions.
Hi Applelight, the strange problem you have could be because you moved the special building before you digged out the purple box. Purple treasure box generally come with special building and i did not see any around the box, but this is just a guess. The other option you can try is to select other than Dig let the map…