Thanks everyone!

As you all can see there is no clear procedure here. The US governmental sites are contradictive in the way that one says "no problem" but the other one says "problem". At the same time one says to send in the original boarding pass to London, KY while the other one says to hold on to it until the next re-entry to US. The only common thing is that you are not allowed to neither call nor ask for status..

I'll see what I will do.