Cross twisting mechanism thread part problem

[Liuna]

I got this Cross and I'm not sure if it was bad before, but I accidentally pulled the threaded inner part out with the refill. The whole mechanism (silver tube sticking out of the bottom part) doesn't stop at any point, I can twist it endlessly. Also if I push it down (the silver tube), it can move a bit down (I have a black Cross, its tube stays form when I push its edge down). There's a very bit of a space between upper and the bottom part when the refill is in. The refill can be fixed in the threaded part with no problem.

Also, it seems the threaded part is a bit deeper inside the working black pen's mechanism than in this one. 

 

I'd like to ask what could be done to fix it (I know of he lifetime warranty, I'm in Hungary though).