I am sorry for your troubles. I don't have any direct experience in dealing with the Virgin fraud team and in fact you might be the first report I have ever read of somebody being impacted by them (reports are more common for BA, AA, Aeroplan, etc.). In any event I don't see anything in your explanation that I would identify as the cause but maybe somebody else has an idea. I am not familiar with German or EU consumer law but in the US if I had purchased points in the last month or so and then the airline had took them away I would file a chargeback with my credit card company.