iPhone or Android? I run the game on PC using BlueStacks and toggle between that and my Android. As long as I have my Google Play account logged into both it works fine.
Exactly the same experience, I think I made it through all 50 tiers withing a few days and now just watch it tick away. Could extend it or increase the grind a bit of the 50 tiers.
I'd like to see these be made available to purchase standalone through the character tab or have it's own tab in the exchange. Don't think they necessarily need to be available free, but I think the game would make more money as more people would buy them if they were available any time.