After almost a month of waiting the support managed to fix my account. Since then I use the XBOX mostly for streaming TV from Watchever.de. It’s working not exactly stable and the program choices are somewhat limited. I have to pay xbox live gold fees + watchever fees which total at approx. 12€ / month. So the only justification for using the xbox is that watchever only runs on Windows (and on Linux using pipelight, a software running silverlight in a virtual machine). All in all I’m not too happy with this setup. I guess I have to move on to the next provider…