Your purchases should sync automatically as long as you're connected to the same Apple ID. However, if you find you're missing your purchased Towers or Heroes, please follow these steps:
Go to the game’s map and tap on Settings:
Then, select “Restore purchases”, this way you should obtain your past purchases again.
If the problem persists after these steps, please send a ticket to our Support Team with a screenshot of your purchase invoices. We'll send you a link to restore your purchases as soon as we get them!