The best way to contact us about a TSG.STORE issue is to write to us from within the game. After logging into the game, select Settings → Help Center → new chat. This will allow us to see your Player ID and account history, and ensure that nobody is impersonating you. It's the fastest and safest way to get a response from us.
Also take a look at our TSG.STORE FAQ – you may find the answer to your question there.
If you want to write to us about any other issue, please use our contact form.