Got a refund for a purchase I didn't make, and it subtracted diamonds I never had, putting me in debt & blocking me from playing. Customer support gave me no option to address the issue, so I uninstalled it. Game is fun, good graphics, but it consistently matches Tier 1 against Tier 3 tanks; it's unfair & discouraging when you can't pay for the best upgrades. UPDATE 3/22/2022: Game still heavily biased in favor of paying players; devs don't seem to care.