I finally got the blowtorch vehicle kill and unlocked the QBZ-95B.
I equipped it and according to battlelog I ran around with it for 51 seconds and fired 26 rounds and then got disconnected from the session.
Next game the QBZ-95B is no where to be seen.
I'm guessing the game totally forgot that I had finally managed to torch a Tank without the guy jumping out due to the disconnect.
I don't think words can express how this made me feel after how long I've been gunning for that last assignment so here is a ditty tune that I think sums it up.