Reporting this sort of  action to your main store provider (apple or google) should be your first course of action. 

Developers that ban accounts for refunds are potentially in violation of their ToS with the host. (I say potentially, because there could be a good reason for this)

However, you should neither have to pay to have your account reinstated, nor be penalized for mistakes. 

Plarium have an obligation to their customers which they are falling behind on, as their "Support" is nothing more than auto replies that are never responded to, leading their paying customers to simply not want to use their "support" channels and go elsewhere. 

I would like to see a moderator or Plarium Employee acknowledge posts like this to show that at the very least, Plarium is taking their support cases more seriously than they appear to be.